This thesis designs optical switches with thermal compensating mechanisms, and then analyzes their thermal responses. First, a novel optical switch with thermal compensating mechanism is proposed, and then a parametric design program is developed for automatically generating the solid model of the switch. The solid model of the switch is exported in ACIS SAT file format to finite element software ANSYS for thermal analysis. According to the BELLCORE specifications, loadings and boundary conditions are defined and applied to the finite element model. The temperature distributions and thermal deformations of the switch are computed by ANSYS. Finally, a prototype of the switch is manufactured. It is assembled on a precision table with CCD image processing units and PZT stages for precision alignment. The packaged optical switch was tested according to BELLCORE specifications. According to results of analysis and experimental measurement, it shows that the developed optical switch can compensate for the misalignment between the input and output fiber tips when ambient temperature varies, and the optical loss can be avoided.