The invention discloses a micro-application / network transmission / physical (Micro-ANP) Micro-ANP communication protocol model architecture method of an underwater acoustic sensor network (UWSN). The method comprises three parts, i.e. Micro-ANP protocol stack hierarchy classification, Micro-ANP network transmission layer protocol composition and grouped format design, and the optimization of UWSN pack load length. Due to the concise protocol hierarchies and unique network grouping format of Micro-ANP, multiple addresses, first length, calibration, upper protocol type and other packaging, brought by a traditional hierarchy model, can be reduced, and the problems that in a sensor node, uplink protocol stacks cannot be too complicated due to computation, storage, energy and other extremely limited resources can be solved; and due to the optimized design of the UWSN pack load length, the energy and the consumption of end-to-end delay and other resources can be reduced, and simultaneously, the network throughput and the transmission reliability are improved. The Micro-ANP communication protocol model architecture method of the underwater acoustic sensor network is applicable to network communication of underwater data acquisition, environment monitoring, disaster prevention, resource monitoring and other application based on the UWSN, and has good application prospect as an effective and practical technical scheme.