The observer designing for a type of switched linear singular systems was discussed. Firstly, the sub-observer of the No.i sub-systems was designed, then when the No.i sub-systems was activated, the observer of switched singular systems can be formed by using the No.i sub-observer. If lingering time of full-dimensional observer whose each sub-system is checked is enough, state estimate error can converge to zero. In some case, state estimate error converge to zero by exponent under any switching.
