This paper designs and implements an improved personal location beacon （PLB） for maritime search and rescue. The PLB has the functions of Beidou navigation and positioning， Beidou short message communication， human vital signs monitoring and reporting， and water touch trigger. What’s more， the proposed PLB supports the COSPAS-SARSAT system. To extend the working time of the PLB， this paper introduces a dynamic power management method to conduct the power channels of different functional circuits. Meanwhile， this paper designs an ultra-low power consumption standby circuit and low power consumption software control scheme to reduce power dissipation. Finally， the prototype of the PLB is tested， respectively， in the adjacent sea areas of Weihai City in Shandong Province and Ningbo to Zhoushan City in Zhejiang Province. The test results of the prototype show that in the standby state， the current of the PLB is 2.3 A， with a standby time exceeding 5 years； in the state of receiving the Beidou short message， the current is 79 mA； and in the state of transmitting rescue messages， the 7 000 mAh 7.4 V battery can send 200 distress messages. Compared to existing products， the proposed PLB in this paper for maritime rescue has lower standby power consumption.