Combined with the principle of bypass switch protection stage 1 (82BPS-1), the action reason and existing risk of 82BPS-1 protection in Puer-Qiaoxiang UHVDC on September 10 of 2015 is analyzed. Then the defect of bypass switch protection is found that the unreasonable integral counting module can make 82BPS-1 protection maloperation. Aiming at the problem, an improved measure is proposed which using the bypass switch closing order to clear the count of 82BPS-1 protection integral counting module. The effectiveness of the measure has been verified by RTDS simulation tests. At present, the improved measure has been applied to Puer-Qiaoxiang and Chuxiong-Suidong UHVDC transmission systems.