A continuous parallel collection system for multiple nuclear radiation data types with Multiple Serial ports Mapped to TCP ports(MSMTPS) is designed and implemented in order to deal with the problems of compatible parallel collection of multiple data types, lack of access serial port resources for the computer, and high bit error rate of collected data transmission. The ethernet is adopted to realize the interaction between nuclear radiation data acquisition system and computer. The system is composed of STM32F103 processor and W5500 ethernet chip, with multiple serial ports capable of interacting with ethernet ports simultaneously. By allocating queue buffers for serial ports that receive different radiation data, mapping multiple serial ports to the same TCP port, and establishing a connection with the host computer based on the TCP port, the fast bidirectional transmission between multiple serial ports and a single network port is realized. In the test, three serial ports are utilized to send 498 bytes, 499 bytes and 499 bytes of data at 0.5 s, 1 s, and 5 s intervals for 10 min. The results show that the system is stable and error-free, which meets the design requirements.