Release-launch is a fundamental operation in space platform. Not like traditional land-base launcher, space-base launcher is more flexible and more efficient. Tubular linear electromagnetic launcher (TLEML), which provides higher force density, simple structure and no unilateral magnetic force, compared with the flat linear electromagnetic launcher, is more suitable for space platform. It can easily meet the demand such as little volume, light weight and high control precision. This paper analyzes and optimizes the thrust characteristics of tubular linear permanent magnet synchronous motors (TL-PMSM) for electromagnetic launcher, including different topologies, interior permanent magnet (IPM) and surface-mounted permanent magnet (SPM). First, build up the finite element model for the two kinds of TLEML and calculate the magnetic field. Then thrust force fluctuation figures are obtained by finite element analysis considering the pole/arc ratio, the pole pitch and the inner diameter/outer diameter ratio of the stator. The result shows that it can improve the thrust characteristic and decrease the cogging force by optimizing the parameters of the motor.