When GVF in the inlet of the oil-gas mixed transmission twin-screw pump is high, the temperature difference between the inlet and outlet of the screw pump will rise significantly, androtor expansion jamwill occur. To prevent the expansion jam caused by the overheating of the screw pump, the cooling water jacket is designed for gas-liquid mixed screw pump with high GVF to continuously cool. Using the theory of fluid-structure interaction heat transfer, the cooling effect of the cooling water jacket of the equal pitch screw pump and the variable pitch screw pump is numerically calculated, and after comparison with the experiment, it finds that the maximum deviation of the outlet temperature of the variable pitch screw pump does not exceed 4Kand the average deviation is about 6 %.When GVF is 96%, the calculation of the cooling water cavity shows that the average temperature drop of the liner after the cooling of the equal pitch screw pump and the variable pitch screw pump is about4Kand3K, respectively. When GVFrisesfrom 90% to 99%, the average temperature drop is about 3.5K. Cooling water jacket has obvious cooling effect on screw pump with high GVF.