Aimed at the defect that radar detection performance can't be fully displayed by using surface rendering, an algorithm of radar detection probability visualization using directive volume rendering technique based on 3D texture is proposed. According to the characteristics of radar detection data such as uneven distribution and inconsistent significance, design principles of the transfer function is given, and then the analytical formula is presented based on the principles. 3D radar volumetric data is calculated based on the advanced propagation model, and the probability is classified by assigning optical imaging parameters through color transfer function. The angle on the condition of the worst visual effect is computed through mathematic model, and experiments have validated that method that replaces real-time slicing calculation by prepared three schemes is feasible. Simulation results show that, compared with the surface rendering, the display of radar detection whole coverage by new version is clear and the internal data can be easily exhibited by cutaway view.