In order to solve the problem of complex system in the security field by theory and computer， the objectives, conditions, and characteristics of incompatible problems in the field of security were defined from the perspective of acceptable security state value and the four elements of security on the basis of studying the theory and method of inconsistent problems, and the corresponding mathematical model was given. The key conjugate elements for the extension of the incompatible problem were defined: The hard part was the safe person and the safe thing, and the soft part was the safe society and the security system. The mathematics strategy to solve the incompatible problems in a gas station, the result showed that the application of this method could solve the problem of the safety of the gas station and provide the new ideas and the basis for safety performance management.

Explosion accidents of pressure pipes occurred frequently in recent years. In order to ensure the safety of people's lives and property and effectively prevent pressure pipeline explosion accidents in the process of oil and gas transportation, this paper uses the triangular fuzzy theory to obscure the probability of the basic event of the fault tree, the logical algorithm, and the significance of the basic event in triangle. Via combination of triangle fuzzy mathematics with fault tree, a pressure vessel fault tree chart has been made so as to calculate the distribution range of top-tiered event probability and determine the order of basic event fuzzy importance. According to the calculation, the priorities of the basic events to improve the reliability of the pressure vessel piping system and prevent the explosion accident of the pressure piping are as follows: man-made destruction, aging of the insulation layer of wires near the piping, excessive current in the control room, poor valve seal of the control piping, poor flange seal of the piping and non-standard operation. In light of the fuzzy importance of basic events, the preventive measures of accidents are put forward.

The DEMATEL algorithm is an algorithm for analyzing the relationship between the influencing factors of complex systems. The algorithm has important application value for identifying the key factors of complex security system. First, on the basis of the DEMATEL algorithm, according to the knowledge of cognitive psychology and the status quo of the safety management of a gas station, the complex gas station safety system is divided into 4 subsystems, and further refined into 31 specific factors. Secondly, according to the DEMATEL algorithm, the MATLAB program is compiled to divide the cause factors and the result factors, and the influence degree, cause degree and center degree of each factor are calculated. Finally, the location of the key factors are displayed intuitively by drawing the cause results diagram. The results show that the information channel interruption, lack of recognition and information uncertainty, contingency plans and response defects are the key factors affecting the safety of gas stations. The longterm solution for gas station safety management is to control these 4 factors.

Eccenter arm is an main part of VSP logging tool, which can make a VSP logging tool lean against the well wall and test stratum parameters exactly. Basing on finite element technology, using ANSYS software, static analysis and modal analysis were made for eccnter arm. Static analysis shows that eccenter arm satisfies strength and stiffness requirements. Modal analysis demonstrates that the first sixth-order natural frequency and vibrancy mode are obtained and sensitivity of feature parameters related to natural frequency was calculated. The reasearch offers a theory guidance for preventing resonance.