Provided is an improved lavage syringe. The improved lavage syringe includes a drip bucket, an infusion adjusting clamp and a tee pipe, a cavity is formed in the inner side of the drip bucket, the upper end of the drip bucket is provided with a puncture pipe, the lower end of the puncture pipe is hermetically connected to a medical two-way valve, the lower end of the medical two-way valve is hermetically connected to the cavity, the lower end of the drip bucket is provided with a first lavage pipe, the infusion adjusting clamp is installed on the outer side of the middle end of the first lavage pipe, the tee pipe is hermetically connected to the lower end of the first lavage pipe, the tee pipe includes a main pipe, the outer side of the middle end of the main pipe is hermetically connectedto a branch pipe, a first narrow throat is formed in the upper end of the branch pipe, the lower end of the first lavage pipe is hermetically connected to the outer side of the first narrow throat, the left end of the main pipe is provided with a dosing pipe, the dosing pipe is connected to a syringe body, the syringe body is installed on a syringe pump, a second narrow throat is formed in the right end of the main pipe, the outer side of the second narrow throat is provided with one end of a second lavage pipe, the outer side of the other end of the second lavage pipe is connected to one endof a connecting pipe in a clamping mode, and the other end of the connecting pipe is connected to a syringe pipe in a clamping mode.