With the fishermen's life on the southeastern coast in the early 1960s as its background, the film depicts a group of militia women who work both as fisher women and fighters defending their homes and the motherland.

解放前的浙东沿海，渔民李八十四（于文仲 饰）不堪渔霸陈占鳌（李林 饰）的强取豪夺，和刘大伯（王炳或 饰）一起组织渔工斗争，被海匪杀害，年幼的海霞（蔡明 饰）盼望着解放军的到来，为穷人们报仇。渔村终于解放了，海霞在方指导员 （赵联 饰）的培养教导下，逐渐成长为女民兵排长。解放前逃到台湾的陈占鳌又派海匪黑风（于绍康 饰）来村里和当年的帐房先生尤二狗（陈志坚 饰）接头，妄图里应外合，配合台湾的陈占鳌反攻倒算。他们在岛上制造了一系列破坏活动，在领导和群众的支持帮助下，海霞带领女民兵揪出了暗藏的敌人，破获了敌人要从海上进犯的情报，全岛军民磨拳擦掌，等待来犯之敌......