This paper proposes a UWB/LiDAR indoor positioning method based on improved Beetle Antennae Search Algorithm(BAS) optimized particle filter to address the issues of non-line-of-sight (NLOS) errors in ultra-wideband (UWB) range and cumulative errors in LiDAR impacting positioning accuracy. In order to eliminate NLOS error in the UWB measurement value, the method combines the benefits of high interference immunity and high temporal resolution of UWB with the high accuracy and efficiency of LDIAR. The distance between the combined positioning system and the UWB base station is solved using the LiDAR measurement information. The addition of improved BAS significantly reduces the number of particles needed by the algorithm, speeds up algorithm execution in real time, and successfully slows down the particle degradation issue. The global bit posture is then obtained by the graph optimization-based combination function of UWB/LiDAR. The experimental results show that the improved BAS optimization algorithm only requires 20% particles of the original particle filter algorithm for the same effect, and that when compared to single UWB and LiDAR localization, the localization accuracy of this proposed method is improved by 58.25% and 76.35%, respectively, with good results.