_{:Scandatecathodes have excellent electron emission properties, but they also have some problems such as emission non-uniformity and poor repeatability. To improve the performance of the cathodes, a method of depositing a kind of composite film on the surface of scandate cathode by Pulse Laser Deposition technology was proposed. The film was deposited using zirconium and high-active barium aluminate salt target alternately. In the paper, the coated scandate cathode was prepared, and its electron emission performance was tested. The photo/thermal emission electron microscopywasobserved, and auger electron spectroscopy analysis of the composition and its depth distributionof the cathode was also processed. The research results show that more Ba and Sc content were detected on the coated cathode surface after activation. An active layer with thickness of 110} ~ _{130 nm was obtained. The cathode exhibits great emission performance. At the same time, the electron emission uniformity of the cathode is significantly improved.}