找到问题了，还是pvd初始化时的顺序问题，按照这个配置，就没有问题了


void PVD_Init(void)
{
         EXTI_InitTypeDef EXTI_InitStruct;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR,ENABLE);  //打开PWR时钟

   PWR_PVDLevelConfig(PWR_PVDLevel_2V9);   //设置PVD的探测电压阀值为2.9V。可设置范围：2.2-2.9
    PWR_PVDCmd(ENABLE);     //使能PVD

    EXTI_InitStruct.EXTI_Line = EXTI_Line16;    //PVD连接到外部中断16
    EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Rising; //电压低于阀值为1，高于阀值为0
    EXTI_InitStruct.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStruct);

    NVIC_InitStructure.NVIC_IRQChannel = PVD_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占优先级0
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;      //子优先级0
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

   
       
}