Abstract: In order to measure more accurate uniaxial compressive strength of the rock, based on the lab measuring method of the uniaxial compressive strength, t he paper analyzed the experiment error caused by the specimen size, specimen water content, experiment instrument and other factors during the rock specimen meas uring process in the lab.Thus there was a big difference between the experiment data results processed with the average value method and the actual results.Therefor e, based on the t distribution properties of the normal distribution N (0, 1) in the parameter estimation, a new function related to the mode was applied to analyze the co nfidence interval of the experiment data.In comparison with 46.74 MPa obtained with the average value method, 47.59 MPa of the rock uniaxial compressive strength 0 btained was more closed to 49.00 MPa of the site measured value.The confidence interval analysis method was better than the average value method.