The near acoustic field, forming by the ultrasonic transducer of curved surface structure and the equivalent dynamic phased array structure, was developed by the physical acoustics principle.Meanwhile the numeral simulation about the ultrasonic near field acoustic pressure could be obtained by the means of the mathematics software.With the given operating frequency and material properties,comparing the ultrasonic transducer of the plane structure,the ultrasonic waves excited by two dimensional half sphere shell surface piezoelectric wafer or equivalent phased array could strongly focus in the near acoustic field with highest lateral/vertical resolution and strongest side lobe/grating lobe suppression according to the simulation results of acoustic field directivity.Finally some valuable techniques about the curved surface array optimization design were given.