The manufacturing cost of coaxial optical communication lasers mainly occurs during the packaging process, and the key technology of the packaging process is the coupling alignment of photonic devices. Therefore, a high-precision and high-efficiency alignment algorithm is of great importance to reduce the cost and improve the quality of coaxial optical communication lasers. The traditional alignment algorithm that is currently used has the following shortcomings: (1) it cannot achieve multidegree-of-freedom alignment at the same time; (2) it easily falls into a local extreme point. Particle swarm optimization (PSO) can achieve simultaneous alignment of multiple degrees of freedom, and it does not easily fall into a local optimum. According to the optical principle, the coupling efficiency function of a coaxial optical communication laser can be obtained. Then, PSO can be used to find the maximum value of the function. The simulation results showed that the PSO algorithm could locate 99% of the maximum optical power. Coupling search can be used for coaxial optical communication laser devices using PSO on packaged devices. The experimental results also proved that the PSO algorithm has high reliability and can realize multidegree of freedom simultaneous search.