Low⁃molecular⁃weight isomeric decanol polyether and high⁃molecular⁃weight fatty alcohol polyether were synthesized using a calcium sulfate⁃type (JD⁃20S) catalyst. The raw material conversion rate of the isomeric decanol polyether was determined by gas chromatography, and the structure of the fatty alcohol ether product was characterized by FT⁃IR and 1H⁃NMR. Indicators such as the cloud point and surface tension of fatty alcohol block polyether 4# were tested. The foam height, detergency rate, and other parameters of sodium dodecylbenzenesulfonate (LAS) compounded with isomeric decanol polyether 2#, fatty alcohol polyether 4#, and fatty alcohol ether AEO9 were investigated. The results showed that in the synthesis reaction of isomeric decanol polyether, when the JD⁃20S catalyst was used, the raw material conversion rate reached 92.91%±0.22% (The number of parallel experiments is N=5), which was 23.32% higher than that of the traditional KOH catalyst, indicating that JD⁃20S possesses both high catalytic activity and excellent narrow⁃distribution performance. The actual structure of the synthesized polyether product was consistent with the theoretical design, proving that the target product was successfully synthesized. The cloud point of polyether 4# was only 15.3 ℃, making it suitable for room⁃temperature washing. When m(LAS)/m(isomeric decanol polyether 2#)/m(fatty alcohol polyether 4#)/m(AEO9)=1.0∶0.5∶1.0∶0.5, the initial foam height was (9.4±0.1) mm, and the detergency rate at 20 ℃ reached (84.56±0.31)%. Fatty alcohol polyether 4# exhibits excellent room⁃temperature foam⁃inhibiting performance. Besides automatic dishwashers, it can also be extended to industrial cleaning applications.