With the rapid development of CD/DVD (compact disc/digital versatile disc) technology, the disc rotation speedand the information density have increased greatly to fulfil the demand of high information bit rate transfer. As oneof the most important elements in a DVD pickup head, objective lens actuators are required to provide a more precisemeans to accurately follow the disc deviation. The design of the lens actuator becomes all the more important andcritical. In order to give complete suggestion to the design of the lens actuator, we put forward the movement differentialequations as a new theoretical means to analyse the characteristics of the lens actuator reliably and rigorously. Basedon the theoretical analyses, many important and effective methods are proposed. A typical experiment veritas thatthe performance of our lens actuator head, which adopts these methods, can satisfy the high speed and high densityrequirement of DVD systems.