In order to measure workpiece′s micro-nano three-dimensional topogr aphy,this paper sets up a parallel confocal microscopy detection system based on the pinhole array.Firstly,in order to rea lize the beam splitting in parallel,a pinhole array of 100×100in the copper foil is made by the laboratory′s three-wavelength picos e cond pulse laser processing machine,and the pinhole array′s area is a square centimeter,the average diameter of the pinhole is 43. 6μm,and the spacing between holes is 100μm.Then the Fraunhofer diffraction model of the pinhole array is studied.Secondly,the thre e-dimensional image reconstruction algorithm and laser speckle homogenization are analyzed.Finally,the measuring system makes three-d imensional measurement for coating plate and screw respectively.The experimental results show that the axial resolution of 1μm a nd the lateral resolution of 20μm are attained and the three dimensional reconstruction image is obtained under the condition that the stepping motor moves 1μm per step.This parallel confocal microscopy system greatly improves the three-dimensional testing speed and can satisfactorily meet the general industrial testing requirement.This paper provides a new method of research and applicatio n for parallel confocal detection technology.