In the traditional rendering technology, the calculation of data volume or the fusion process is realized with CPU, which is inefficiency and time-consuming to render massive data volume. To solve this problem, we propose an approach which uses GPU to deal with color calculation and data fusion. This method takes advantage of the parallel processing capabilities of GPU. Data will be submitted to GPU in the form of textures, and then GPU deals with necessary color calculation and data fusion and finally renders them. Experimental results show that the method can make integration of multi-attribute data, organically combines the advantages of each attribute, carries out a comprehensive evaluation of oil and gas reservoirs, and improves the accuracy of reservoir analysis and interpretation. The rendering is accelerated with GPU.