According to the problems of joint test action group (JTAG) being not used during on-orbit satellite controller reconstruction and being difficult to update DSP program due to the limitation of working environment, taking digital signal processing (DSP) TMS320F28335 as an example, a scheme of online reconstruction DSP controller through serial port is proposed. Because the DSP controller may be knocked over by a single particle while the satellite is in orbit, a method of redundancy of the master control program and periodic or instruction reconstruction of the master program to reduce the possibility of invalid of the controller due to the flip of the single particle is proposed. Experimental results show that the method is simple and suitable, stable and reliable operation, and easy to operate, which can realize the reconstruction program of DSP TMS320F28335 take over the controller after power on, solve the problem of reconstruction of DSP in orbit, and greatly reduce the possibility of being knocked over by single particle. It can be applied to the commercial aerospace embedded field.