Abstract: Solar Radiation Pressure (SRP) is one the most important forces impacting the precision of spacecraft's orbit determination and prediction in deep space detection. In deep space exploration mission, there is no special solar pressure model for each spacecraft at present. The usual method is to simplify the shape and structure of spacecraft, and estimate the cross-sectional area and SRP area. In order to improve the accuracy of the SRP model, it is necessary to consider not only the occlusion relationship between different parts of the spacecraft in the light direction, but also the reflection characteristics of different materials on the surface of the spacecraft. Aiming at actual mission requirement, the method of calculating solar pressure area based on target characteristics is studied. Based on the information such as target's shape, size, surface materials and their optical characteristics, the analytical model of SRP is built. According to the relevant parameter information, the normal vector of each micro effective plane element, the angle between the plane element and the incident direction of the light, the type of material represented by the plane element, the relationship between mutual occlusion and the reflection characteristics of the material are calculated respectively. The calculation efficiency and precision is increased effectively, and the target's SRP area, the cross section area and the scale factor can be calculated fast. By comparing with theoretical SRP area of rectangular body, the simulated results are proved to be correct. At last one complex spacecraft's SRP areas are calculated and analyzed. This research can provide meaningful and significant references for the SRP modeling solution, orbit determination and forecasting.