In this paper, a calibration method for the 3D earth pressure cell in sand is introduced. Using two customized calibration cylinders, the influence of the calibration cylinder size, the box size of the earth pressure cells, the capacity and the buried depth on the calibration coefficient of the 3D earth pressure cells in sand and the sand characteristics of the 3D earth pressure cell involving loading and unloading are studied. The results show that: ① The size of the calibration cylinder and the depth of burial have a large impact on the calibration results, whereas for the same range of 3D earth pressure cell, the size of the base and the transducer diameter-tothickness ratio have a smaller impact on the calibration results; ② The hysteresis of the large capacity 3D earth pressure cell is smaller than that of the small capacity cells, and the large capacity cells should be preferentially selected for soil stress measurement. ③ The unloading curve of the 3D earth pressure cell can be normalized by the maximum stress and output voltage value before unloading, and the normalized unloading curves of the 3.0 MPa cell has a small distribution bandwidth for different unloading curves, and the exponential curve can be used for analysis of soil stress measurement.