The invention relates to a self-cleaning and anti-seize tubular pump for a
coal-
bed gas well. The self-cleaning and anti-seize tubular pump comprises a
coupling, a pump cylinder, a self-rotating type combination
plunger, a deposition-preventing fixed valve and a self-cleaning type liquid sucking opening, wherein the upper end of the
coupling is connected with an oil
pipe, the lower end of the
coupling is connected with the top end of the pump cylinder, the self-rotating type combination
plunger is located in the pump cylinder, the upper end of the deposition-preventing fixed valve is connected to the bottom end of the pump cylinder, and the lower end of the deposition-preventing fixed valve is connected to the top end of the self-cleaning type liquid sucking opening; and the self-rotating type combination
plunger adopts a rubber
piston structure and an automatic rotating mechanism. According to the self-cleaning and anti-seize tubular pump, the designed self-cleaning type liquid sucking opening carries out spiral separation on sucked liquid so as to prevent large-particle
coal powder mud from entering the pump, and the separated particles can be rapidly discharged; the deposition-preventing fixed valve is adopted to change the flowing direction of liquid, carry out spiral rapid scouring on
coal powder mud depositing at the bottom of the pump cylinder, and reduce the deposition of the coal
powder mud in the pump cylinder; and as the rubber
piston structure and the automatic rotating mechanism are adopted, the self-rotating type plunger consisting of a flexible seal and a hard seal is formed, and plunger seize failures caused by coal powder mud are reduced.