In this study, in-plane shear tests were performed on 20 masonry wall specimens. The research factors considered included the length, height, thickness, fiber material, and number of textile-reinforced concrete (TRC) layers of the specimens. The failure modes, shear strength, pseudoductility, and energy dissipation of masonry walls under the influence of different factors studied were discussed and analyzed. The results showed that the unstrengthened masonry walls exhibited typical brittle failure characteristics and low shear strength at failure, which could be significantly improved by TRC strengthening. Under the test conditions of this study, the greater the length and height of the unstrengthened specimens with the same thickness, the lower the shear strength, and the higher the percentage increase in the shear strength after strengthening. For unstrengthened specimens with the same length and height, the greater the thickness, the greater the shear strength, and the lower the percentage increase in the shear strength after strengthening. After applying the same TRC layers on double-leaf walls, the shear strength and pseudoductility increased by 107.9% and 9.4 times for carbon-TRC strengthened specimens, and the two parameters of specimens strengthened by basalt-TRC increased by 50.3% and 7.0 times, respectively. In addition, the strength and ductility of the specimens increased as the number of TRC layers increased. Finally, the calculated and design values of shear capacity of each specimen were calculated according to current design standards and compared with the obtained test results. The conservativeness of the related design methods was also discussed.