As the design of phase mask in wavefront coding imaging systems is complex and the aberration of original optics cannot be taken into consideration, two new design methods are proposed based on the popular optical software ZEMAX.By using ZPL macros, the user defined operands are written to optimize the energy concentration and consistency of the point spread function, and the depth of focus of the optimized rotationally symmetric phase mask is 5.5 times as large as that of traditional imaging systems at the criterion of Strehl ratio larger than 0.8.By using an externally defined and compiled C program, the user defined operands are written to optimize the defocus invariance of modulation transfer function, and the depth of focus of the optimized odd symmetric phase mask is 12.5 times as large as that of traditional imaging systems.However,the depth of focus of the cubic phase mask is only 10.1 times as large as that of traditional one in the same condition.These results show that the design methods proposed are practical and effective.