Lock alias analysis can obtain the precise lock pointer information. Efficient lock alias analysis can make a good contribution to data races analysis and deadlock analysis. However, existing lock alias analyses often use a conservative approach, which impacts the accuracy of analysis. This paper proposes a lock alias analysis method. This method firstly gains SSA-form intermediate code by a GCC plugin. Then it preprocesses the intermediate code to obtain the statements related to function pointer and lock operation. Based on this we present the flow-sensitive and context-sensitive function pointer and lock analysis algorithm(referred as FP_LOCK algorithm). Experimental results show that this method has well precision and advances 9.95 times on average compared with the original algorithm.