Abstract: A solar array DC analysis model is introduced in this paper,by exploiting equivalent circuit of solar array which is composed of solar cell series and parallel connected and DC analysis model of cell derived from solid-state physics theory,the output power of solar array on orbit is predicted.The solar array DC analysis model is converted to an equation determined by four parameters:open circuit voltage of solar cell V_oc;short circuit current of solar cell I_sc;maximum power point voltage of solar cell V_mp;maximum power point current of solar cell I_mp.By getting the real parameters of solar array V_Aoc,I_Asc,V_Amp,I_Ampon orbit through obtaining the degradation coefficient for solar cell current and voltage through ground testing.The working point voltage and current of solar array is calculated,and the output power of solar array on orbit is predicted.The prediction model is proved to be effective by comparing the solar array on orbit remote telemetry value of working point voltage and current with the prediction result.The prediction model can get the DC analysis model of solar array with four parameters of solar cell and help to analysis of solar array modeling for engineering application during system design stage.