diff --git a/bsp/at32/libraries/rt_drivers/drv_adc.c b/bsp/at32/libraries/rt_drivers/drv_adc.c
index 73a9c1184c..1a67c490e8 100644
--- a/bsp/at32/libraries/rt_drivers/drv_adc.c
+++ b/bsp/at32/libraries/rt_drivers/drv_adc.c
@@ -135,8 +135,10 @@ static rt_err_t at32_get_adc_value(struct rt_adc_device *device, rt_int8_t chann
     /* adc_x regular channels configuration */
 #if defined (SOC_SERIES_AT32F435) || defined (SOC_SERIES_AT32F437) || \
     defined (SOC_SERIES_AT32F423)
+    adc_flag_clear(adc_x, ADC_OCCE_FLAG);
     adc_ordinary_channel_set(adc_x, (adc_channel_select_type)channel, 1, ADC_SAMPLETIME_247_5);
 #else
+    adc_flag_clear(adc_x, ADC_CCE_FLAG);
     adc_ordinary_channel_set(adc_x, (adc_channel_select_type)channel, 1, ADC_SAMPLETIME_239_5);
 #endif