Data acquisition technology is an important branch of information science, and is the foundation of modern measurement technology with sensor, signal processing and computer technology. The solution scheme, constitution and characteristics of data acquisition system are described. This acquisition system consists of sample-and-hold device, AD converter, CPLD, USB control chip and software design. Using Altera EPM7128 as the core of the controller, a multi-channels data acquisition system based on CPLD is designed, the data can be transmit fast via USB interface. The system can achieve 16 channels input of analog quantities, and the resolution of every channel is 14 bit, the data acquisition rate is 16 Ksps.