Abstract: Basalt fiber is a fiber material with good mechanical properties, excellent corrosion resistance and high cost performance. Incorporating it into 3D printing cement-based materials can inhibit plastic shrinkage and cracking. The addition of basalt fiber will significantly change the rheological properties of 3D printing cement-based materials, which will affect the extrudability and buildability of 3D printing cement-based materials. This article aimed to clarify the influence of basalt fiber on the printability of 3D printing cement-based materials. By changing the fiber content, diameter and length, the effects of basalt fiber properties on the rheological properties, extrudability and buildability of 3D printing cement-based materials were studied. The relationship between rheological properties and extrudability and buildability was clarified. The results show that the amount of basalt fiber has the largest influence on the rheological parameters of 3D printing cement-based materials, followed by the diameter. The dynamic yield stress is negatively correlated with the amount of extrusion per unit time. The static yield stress is positively correlated with the inclination angle of the printed specimen. The cross-sectional area ratio of the printed specimen is affected by comprehensive factors such as dynamic yield stress and static yield stress. Taken together, good extrudability requires moderate dynamic yield stress, about 280 Pa. Excellent buildability requires not only a moderate dynamic yield stress, but also the static yield stress greater than 950 Pa.