In order to meet the requirements for high reliability of space camera controller,a self-testing method of Digital Signal Processor(DSP) space camera controller based on mixed language programming was proposed.With this method,the difficult problem of changing variable locations in RAM according to self-testing results was solved under mixed language programming by modification of runtime-support library.Also,in this way,the image motion compensation algorithm could be realized easily in DSP space camera controller.Experimental results show that the maintainable and transplantable abilities of the codes are improved greatly.Several problems on realization of self-testing arithmetic on DSP repertoire,Read Only Memory(ROM),Random Access Memory(RAM) and other peripherals were analyzed and solved,and an improved peak value test algorithm of RAM was put forward,so that the probability to detect RAM fault with improved algorithm is at least twice as large as that of original algorithm in the same running time.As it is difficult to test self-testing algorithm itself without harming hardware,a method to validate self-testing algorithm was presented.The results of validation experiments and practical application effects in engineering prove that the self-testing algorithm is practical and valid.