Surveys of village buildings frequently reveal a paucity of essential seismic measures, resulting in a deficiency in seismic capacity. In order to enhance the seismic capacity of these buildings, it was necessary to reinforce the walls using polypropylene mesh and composite cement mortar. In order to investigate the seismic performance of reinforced masonry walls with openings, three wall models with openings were designed and subjected to quasi-static tests. The hysteresis and skeleton curves of the model specimens were obtained from these tests. Numerical models were then established using ABAQUS finite element software for the purpose of computational analysis. A comparison was then made between the results obtained from this analysis and the experimental findings, which revealed a high degree of consistency. The unreinforced specimens exhibited initial cracking at the corners of the openings under load, which gradually extended to the wall ends, forming “X” or “/\” shaped continuous cracks indicative of shear failure. Reinforcement with polypropylene mesh and composite cement mortar effectively delayed and mitigated wall damage. The ultimate bearing capacity of walls reinforced on one side and both sides increased by 68.75% and 107.05%, respectively, compared to unreinforced walls. Additionally, the initial stiffness of the walls improved by 11.68% and 46.55%, respectively, while the ductility performance increased by 6.34% and 14.63%. The analysis results indicate that both single-side and double-side reinforcement of masonry walls with openings significantly enhance their seismic capacity. The openings tend to form continuous cracks after initial cracking, and the failure mode differs from that of walls without openings.