Abstract: During the process of trial operation, a large number of solid blockages were formed in the low temperature separator of the natural gas processing plant of a high temperature and high pressure gas field in West China, which caused the blocking of the processing device. Based on the analysis, it was concluded that the major components of solid phase deposition materials were C₁₂-C₁₄. When the operating pressure of the device was 6.85 MPa, the temperature of the device was reduced to -9.5 ℃, the solid crystal was directly precipitated in the gas phase, and the low temperature separator was blocked. The results of field test showed that the temperature of the low temperature separator could be increased appropriately to reduce the formation of solid phase deposition materials to a certain extent, but still couldn't solve the blockage problem of solid phase deposition completely. Combined with the injection of light hydrocarbons, the solid phase deposition could be effectively removed.