The invention provides a method for realizing water sound sensor network MAC (Media Access Control) protocol based on ALOHA and TDMA (Time Division Multiple Access). Based on the traditional TDMA mechanism, in the method, time is divided according to time slot, a semi-duplex communication model is adopted, and long propagation time-delay characteristics of water sound communication and space reusability of a channel, and the ALOHA mechanism competition time slot are adopted under the condition of not affecting main node transmission data and unsuccessfully handshaking with the main nodes and not receiving other nodes of the CTS (Clear To send)frame, and receiving data during the process of confirming outstanding messages and data transmission failure delay transmission process are increased so as to realize communication between one node and a plurality of nodes, network throughput is improved and network end-to-end delay is reduced. The method provided by the invention is suitable for the water sound sensor network and other long propagation time-delay communication networks, is easy to implement and high in actual application value.