If the rotor vibration signals of the turbine are collected in the way of integer period, it would be helpful to improve the precision of spectrum analysis, so as to improve the level of condition monitoring for machinery. Based on a thorough research of the integer period acquisition technology, a design of data acquisition card based on FPGA (field programmable gate array) is proposed, the card is of small size and compact type, and has the ability to collect multi-channel signals in the way of integer period synchronously. The design uses FPG A to realize the integer period acquisition control algorithm, based on the key phase and multi-frequency method, and to control two pieces of high speed A／D conversion chips to collect multichannel signals synchronously in the way of integer period. The ping-pong operation way is used to store those A/D conversion data into RAM memory, and the PC104 bus agreement is used to communicate with the host machine. Test results show that, the data acquisition card can accurately collect multi-channel periodic signals synchronously in the way of integer period, and measure the frequency of the key phase signal, also it has the advantages as follows: small size, high level integration, large range of acquisition frequency and high accuracy of frequency measurement, etc. It can be wildly used in the field of rotor vibration signal′s acquisition.