The ultrasound has attracted much attention in the fields of biomedicine and industrial nondestructive evaluation due to its noninvasive property.As the key method for ultrasonic application, ultrasonic transducers often need high spatial resolution and specific sound field distribution.The common single element transducers need to be optimized to meet the abovementioned requirements, and focusing is the most direct and effective method.For ultrasonic transducers with different types and processes,various focusing processes are proposed to optimize the performance of transducers.