To investigate the evolution of splitting tensile strength of low-heat cement concrete with varying basalt fiber lengths, contents, and curing ages, splitting tensile tests were conducted on 160 specimens using the control variable method at a loading rate of 0.05 MPa/s. The influence of basalt fiber content and length on the splitting tensile strength at different curing ages was analyzed. The results indicate that under conditions of varying basalt fiber content and length, the fibers enhance the splitting tensile strength at all ages, although the impact patterns differ significantly. When the fiber length was 12 mm, an increase in fiber content led to an initial rise followed by a decline in tensile strength at ages of 3, 5, 7, and 14 days, reaching a peak at a fiber content of 0.2%. When the fiber length was 24 mm, the splitting tensile strength exhibited an initial increase followed by a decrease as fiber content increased. Except for the 14-day curing age, the maximum strengths at all other ages were achieved at a fiber content of 0.2%. The optimal basalt fiber length and content were determined to be 12 mm and 0.2%, respectively.