In the MIMO-OFDM detection algorithm, the performance of sphere decoding most approach that of the Maximum Likelihood algorithm. However, the complexity of traditional sphere decoding algorithm is still relatively high. To solve the above difficult problems, some improvements are made based on the detail analysis of the principle of the sphere decoding algorithm. In this paper, a novel variable radius sphere decoding is proposed. We introduce a golden section search algorithm to accelerate the convergence rate of the original algorithm. Thus it greatly reduces the complexity of the algorithm. Compared with the traditional sphere decoding algorithm, the proposed algorithm can greatly reduce the complexity of the receiving decode testing process. Thus this algorithm is more suitable to the real-time requirements of the TD-LTE system.