The invention discloses an adjustable water-injection 
ablation electrode needle, and belongs to the field of operating instruments for 
electrosurgery and the field of operating instruments for minimally invasive 
ablation. The 
electrode needle comprises a needle rod, a 
handle, an adjusting knob, an adjusting sleeve, a 
scale sliding block, a needle rod fixed seat, a 
water pipe fixed seat, a 
water pipe and 
radio frequency cables, wherein the tip end of the needle rod is composed of a triangular blade which is easy for puncture, and a thin hole is formed in the needle rod; an annular groove is formed in the 
handle, and a length-adjusting graduation ruler is arranged on the edge of the annular groove; an outer 
screw thread is formed in the adjusting knob, and the adjusting knob is composed of a plurality of edges provided with rounded corners; the adjusting sleeve and the 
scale sliding block are bonded by virtue of glue; an inner 
screw thread, which is matched with the adjusting knob, is formed in the 
scale sliding block; a scale indicating line is printed on the scale sliding block; the needle rod fixed seat and the needle rod are connected by virtue of glue; the 
water pipe fixed seat and the water 
pipe are connected by virtue of glue; and the 
radio frequency cables are welded on the needle rod. The adjustable water-injection type 
ablation needle disclosed by the invention is convenient to operate and clear in scale, and the ablation needle is convenient for doctors to observe in an operation.