Compared with the calibration coefficient K of earth pressure cells in practical application in civil engineering, K values provided by manufacturers have certain errors. To solve this problem, calibration tests were performed on different kinds of earth pressure cells, and differences between K values of different kinds of earth pressure cells obtained from calibration tests under the same embedded conditions, as well as the reasons, were analyzed based on their operating principles. Three kinds of typical earth pressure cells(single-film vibrating wire, double-film vibrating wire, and resistance strain gauge earth pressure cells)were selected for calibration tests in sand soil. The test results were compared with the values provided by manufacturers, and a linearly fitting formula based on test results was used to calculate the calibration parameter of different kinds of earth pressure cells in sand soil. Test results show that the K values are 50% smaller than those provided by manufactures for vibrating wire earth pressure cells, however the K values are four times those provided by manufactures for resistance strain gauge earth pressure cells.