Detector readout and display and analysis of data are key issues to host computer software. Aiming at features and software demands in deep-sea in-situ nuclear radiation detection, this paper designs a detector software which integrates detector control and readout and display and analysis of data. A protocol based on MODBUS is designed, the work pattern of detector and a unified hardware interface are defined, and drivers for RS-485 and Thunderbolt are implemented in the software for detector readout. User interface is designed by XAML for data display. An algorithm based on wavelet transform and expectation-maximization algorithms for peak finding, fitting, and nuclide identification is designed. By connecting to detector to measure and analyze spectrum of balanced 238U-226Ra source and known radioactive samples from deep sea, the functions of the software are tested. The results shows that the software can stably realize detector configuration and readout, as well as data display and analysis, and has a better analysis result than InterSpec, a spectrum analysis software.