Confocal microscopy has been widely used in biomedicine,materials sc ience,industrial testing and other areas for its unique optical sectioning property,high lateral resolution performance and nondestructive detection.Since confocal microscopy takes lateral detection poin t by point,which can only get the information at one spot a time,3D scanning becomes necessary in th e process of confocal measurement.The traditional methods of confocal scanning are mechanical means,o f which the characteristics or mechanical driving technology limitations could not meet the requirements of live cell imaging and other application areas.Aiming at the shortcomings of mechanical sc anning methods,the technology of controlling the three-dimensional position of focusing spot based on phase-only liquid crystal spatial light modulator (LCSLM) is researched,the confocal three-dimens ional scanning system with no mechanical moving parts is designed,and the three-dimensional scanning of m icroscope objectives of focusing spot is realized.The main method is the modulation of the incident light on the phase and amplitude with liquid crystal spatial light modulator.The results prove that the scanning method can be achieved and the max- imum deflection angle is 0.021 rad,absolute error of beam de flection is ｜θerror｜＜3．30×10－8 rad≈ 1．89× 10－6,and the axial scanning range that can be realized is ,[－55.6mm,55.6mm].