Based on 3D printing technology, this paper investigates the effects of the printing process and reinforcement materials on the performance of 3D-printed glass bead insulation mortar. In order to improve and enhance the performance of the mortar, two sets of tests were designed for research and analysis. Firstly, by changing the direction of the interlayer printing strips, the anisotropy of the specimens in different paths was analyzed, and then the effect of different dosages of different fibers on the performance of 3D-printed glass bead insulation mortar was investigated by adding reinforcing materials. The results show that the path a specimen in the X direction’s compressive strength is the best; in the Y direction, flexural strength is the best; the path b specimen in the Y direction’s compressive strength is the best; in the Z direction, flexural strength is the best, but the compressive and flexural strengths are lower than the strength of the specimen without 3D printing (cast-in-place specimen); and adding reinforcing materials mortar not only has high strength but also has good printability and excellent thermal insulation. This paper provides a theoretical basis and reference value for the popularization and application of 3D printing thermal insulation mortar technology.