The phased array ultrasonic detection provide a method for the inspection of surface crack in turbine blade.A phased array ultrasonic transducer with wedge is designed and fabricated.The transducer is a linear phased array,its element numbers are 32,center frequency is 5 MHz, the element width is 0.3 mm and the element space is 0.1 mm.The wedge can couple with the surface of blade completely. The feasibility verification of the transducer and the wedge design is carried out by using the finite element method.A phased array ultrasonic detection system is set up to conduct the experiment on the turbine blade sample.The experimental results show that the proposed transducer with wedge can achieve the inspection of the surface crack in the turbine blade.