This paper introduces one kind of method based on the MATLAB C-MEX modeling for all-digital single phase grid connected inverter. The main circuit is built by discrete device, and the module of C-MEX is compiled with the C language source code, which can be transplanted directly into the embedded development platform to improve the development efficiency. The control method of MPPT at DC side is disturbance observation method, and the control method of AC side is based on voltage outer loops and current internal loops, which contains the control methods of DC magnetic bias suppression, virtual single-phase phase-locked loop and the PR regulator. Finally, on the basis of this modeling and simulation, a 3 kW single phase photovoltaic grid-connected inverter is developed, and then the C source code is transplanted into DSP embedded development platform. The test results show the superiority of this development pattern and prove that the simulation model is correct.