Load spectrum is the data base for life prediction and reliability analysis of the systems and components in excavators, and the differences between load characteristics well affect the prediction and analysis results. Operating characteristics of operators are important factors that affect the load characteristics, especially the load centralized locations and load fluctuations. Load of the main pump pressure in the hydraulic system of an excavator was tested under the operations of three different operators. After the load processing and segments, load of the digging section was extracted, then the mean value and standard deviation of the load with different operators were obtained. Based on the fitting chart and K-S testing method, the mean value and standard deviation were proved to fit the normal distribution, and the otherness of the characteristic value between different operators was analyzed with the significant difference theory. It testifies the objectivity of the influence of the operating characteristics on the load characteristics, which provides theoretical foundations to pay attention to the effects of human factors on load characteristics in the field of construction machinery.