Abstract: Aiming at the problem of coal fines plugging in the screen tube of coalbed methane wells, a two-dimensional and three-dimensional simulation models of the screen tube for coalbed methane wells were built with the help of COMSOL finite element simulation software, and the effect of ultrasonic action position and frequency on the sound pressure and the uniformity of the sound field in the screen tube area was studied by numerical analysis, and the possibility of using ultrasonic to unplug the screen tube was discussed. The results show that the sound pressure produced by ultrasonic can reach the minimum pressure value of cavitation effect, and it has the effect of unplugging the screen tube blocked by coal fines. When the ultrasonic wave acts on the center of the outer wall under the screen tube and the center of the inner wall under the screen tube, the change trend of the sound pressure amplitude is basically the same. The sound pressure amplitude is large, but the distribution uniformity of the sound field is poor. While the ultrasonic wave acts on the center of the screen tube, the sound pressure amplitude is small, and the distribution uniformity of the sound field is good. The absolute sound pressure and sound field uniformity show an overall upward trend with the increase of ultrasonic frequency. At the frequency of 60 kHz, the absolute sound pressure and sound field uniformity are larger and better. In the frequency range of 20 kHz to 40 kHz, the absolute sound pressure and sound field uniformity vary in a low range. In the frequency range of 40 kHz to 60 kHz, the absolute sound pressure and sound field uniformity fluctuate greatly with the change of frequency. Using ultrasonic technology to unplug the screen tube, if the ultrasonic wave acts on the center of the outer side wall under the screen tube and the center of the inner side wall under the screen tube, the ultrasonic frequency should be 50 kHz or 60 kHz; and if the ultrasonic wave acts on the center of the screen tube, the ultrasonic frequency should be 30 kHz or 60 kHz. In both cases, the absolute sound pressure in the screen region is larger and the sound field uniformity is better, the cavitation degree is higher, and the unplugging effect is better.