Localization has great significance for theoretical study and practical applications in wireless sensor networks. Meanwhile, security has been a serious issue and great challenge for the development of localization technologies since attackers can alter localization information to affect the accuracy of localization results. In this paper, we propose a novel secure localization scheme based on signcryption (SLBS) that will allow sensors to assure the confidentiality and integrity of their location information. We perform analysis to explain why SLBS can enhance the security and accuracy of localization through the signcryption mechanism and simulation to verify the performance of SLBS. The analysis and simulation serve to demonstrate that SLBS can effectively reduce localization errors in hostile environments and keep the distance measurement errors within a small range.