Abstract: Single pass surfacing experiments were carried out by using CMT+P mix transition welding with different CMT(cold metal tarasfer)ratio on 10 mm thick TA5 titanium alloy plate.The results show that the single pass weld section is portal arch under big CMT ratio, which is not conductive to wettability of weld pool on the plate and effective deposition of the weld.When the number of CMT is kept as 1, the effect of the change of pluse number in a cycle on the wettability is not obvious.While the high Pluse/CMT transfer frequency leads to greater spatter.The weld formation is smoother and the spatter is lower when the Pulse and CMT numbers remain 60 and 20 in a cycle respectively.The DR test results of the welds show that there are no pores and other defects in the joint.The metallographic and hardness tests of the welded joints were carried out.The weld zone has no hardening phenomenon, which fulfills the use requirement, and the grains of weld zone of CMT-P mix transition are finer.