Dissolved organic carbon (DOC) is the largest organic carbon pool in natural water body. The transport process of DOC is an important part of the carbon cycle in watersheds, which has significant impacts on the global carbon cycle. In order to investigate the characteristics of stream DOC flux and its influencing factors during the spring freeze-thaw, the rainfall, air temperature, soil temperature, daily runoff and daily stream DOC concentrations in a permafrost small watershed of Laoyeling in the Da Hinggan mountains were observed during the freeze-thaw period from April 9 to June 30 in 2021. The stream DOC flux was calculated from the freeze-thaw cycle period (April 9-28) and the thaw period (April 29-June 30), respectively. The results showed that:(1) during the study period, the stream DOC concentration in the study watershed varied in the range of 3.88-33.75 mg/L. The change trend of stream DOC concentration in the upper stream is consistent with that in the downstream of the study watershed. The average stream DOC concentration was significantly higher in April than that in May and June, and showed a decreasing trend associated with the increase of air temperature. (2) The total stream DOC flux was 3215.48 kg/km² in the watershed during the study period, of which the stream DOC flux in May was higher than that in April and June. The stream DOC flux showed a significantly positive correlation (P<0.05) with the runoff, which was the dominant factor controlling flus of stream DOC in the study watershed. (3) During the study period, stream DOC concentration was significantly negatively correlated with air temperature(R²=0.5048,P<0.001). The variation range of DOC concentration in precipitation samples was 1.06-9.42 mg/L, which was much higher that of stream The dynamic of DOC concentration in soils was consistent with stream DOC. The average DOC concentration in 0-10 cm and 10-20 cm soil ranged from 77.57 to 133.99 mg/L.(4) The mean daily stream DOC concentration was significantly (P<0.05) higher during freeze-thaw cycle (24.02 mg/L) than that during thawing period (14.64 mg/L), while the mean daily DOC flux during thawing period (48.02 kg/km²) was five times higher than that during freeze-thaw cycle period (9.52 kg/km²). The results reveal the transport characteristics of stream DOC and its influencing factors during the spring freeze-thaw period in a small permafrost watershed in Da Hinggan Mountains, which is of great significance for understanding the carbon cycle in the permafrost region.