Photoacoustic microscopy (PAM), whose image quality largely depends on the optical absorption of samples, provides endogenous information for structural and functional imaging. However, PAM technology in general can not provide edge enhancement imaging for absorbing objects. Therefore, PAM and differential microscopy are integrated for the first time in a single technique to obtain an edge enhancement image. The resolution test target RTA-07 and red blood cells are used as samples to achieve the desired spatial differential photoacoustic imaging. The feasible biomedical application of edge enhancement from the improved differential PAM was demonstrated.