This paper investigating an ironless linear synchronous motor with cooling system. Firstly, topology of this ironless linear synchronous motor with cooling system is introduced. Flux density in the cooling system is obtained analytically by the separation of variables method according to the boundary conditions. The eddy current braking force introduced by the cooling system is calculated and validated by finite element method. The motor parameters are optimized to improving the eddy current braking force. At last, a prototype motor is designed and established to validating the analysis and optimization results.