Based on the sand discharge principle and flow balance theory of spiral seal structure,the corresponding flow channel models of serrated,rectangular,trapezoidal and semicircular spiral teeth were established,and the sand discharge performance evaluation criteria was established.Combined with fluid turbulence model and solid particle trajectory tracking method,the velocity field,pressure field and cuttings retention time of different profiles were analyzed,and the influence of profile on the sand discharge performance of spiral seal was studied.The sand discharge performance of different tooth profiles was evaluated,and the spiral seal tooth profile was optimized.The results show that all four spiral profiles have the ability of active sand discharge.The pressure difference between the two ends of serrated seal channel is the largest,which can produce a larger pumping flow,and the debris particles are easier to discharge.At the same time,the retention time of debris particles in the serrated seal is the shortest,so the serrated spiral seal has the best sand discharge performance.The optimization results show that the sand discharge performance is the best when the pitch is 3.2 mm,the working face inclination is 3° and non working face inclination is 30° of the serrated spiral seal.