As a part of the reflectometer in China Spallation Neutron Source (CSNS), data acquisition system (DAQ) of 3He tubes detector should not only have basic functions of data readout and processing, but also coordinate the whole operation of spectrometer and interact with other heterogeneous systems stably and reliably. By planning the whole frame, adopting effective methods, optimizing the key components of DAQ system, choosing and integrating appropriate third-party software, DAQ system achieves goals of convenient and flexible operation, having complete functions and running stably, reliably and efficiently. It meets the demands of the reflectometer. The reflectometer with the DAQ has passed national acceptance. By now, this DAQ system has been applied in neutron beam tests on the reflectometer successfully.