The data logging and management system (DLAM) of the autonomous underwater vehicle (AUV) running on the on-board PC/104 module uses the synchronization and communication mechanism by using multi-threading to implement the function of the collection of data from different devices through multi-serial-port card for sonar, compass, gyro and the USB port for accelerometer, as well as the function of enveloping and transmitting the data to the on-board Industrial PC (IPC) via Ethernet and the function of managing and recording the data locally. Circular buffer management class designed by ourselves and the sequence table are used to manage the data in the memory. By using the circular buffer, we can be free from those trivia like allocating and releasing the resources of memory all the time. The software reliability is analysed and evaluated as well. White-box testing method is employed to test the system, and Musa execution time model is used to estimate the reliability. The result of the estimation shows that the system achieves the expected requirement.