A new microfabrication technology based on PMMA(polymethylmethacrylate)microneedles was presented by using the PCT technology with X-ray and lithographic mask. By moving lithographic mask, three-dimensional PMMA microstructures could be made,and the fabricated shape was directly dependent on the absorber pattern on X-ray mask. From the experiment, the final microstructure was not the same as the absorber pattern on X-ray mask. Experiments show that if there is no compensation for mask design, the shapes of sloped side-wall on the exposed structures will be deformed, which affects the performance of microneedles. The main reason of the deformed shapes of sloped side-wall was analyzed in this paper,and results show that it comes from nonlinear relationship between developing time and exposure energy. Based on the PCT method of fabricating PMMA microneedles, the length of the microneedle is 100-750 μm, and the diameter is 30-150 μm, which means that the minimum of the microneedle’s diameter is 100 nm. Based on the compensation of the mask pattern, the strength of microneedle with the channels has been improved by changing the mask pattern from a hollow double right-triangular pattern to a hollow double semi-elliptic pattern.