The net position, net body status and overall status of trawl are important indices to evaluate the trawling performance during trawling operation. The trawl operation status of an Antarctic krill trawl is expressed by the depth difference between the different parts of the trawl (headline, section 3-4 net body connection, upper midpoint of the cod-end mouth). In order to determine the trawling status of midwater trawl,the effects of fishing operations, marine environment and catch on the status of trawling operations were investigated in this study. The results showed that:The depth difference between the headline and the section 3-4 net body connection range from -0.20 to 8.02 m, and the depth difference between the headline and the upper midpoint of the cod-end mouth ranged from 6.49 to 30.16 m; Warp length, towing speed, wind speed and water velocity at 150 m depth had significant effects on the depth of the headline (P<0.05); The headline depth was positively correlated with the warp length and water velocity at 150 m depth, there was a negative correlation between the headline depth and towing speed, and the headline depth decreased first and then increased with the increase of wind speed; Towing speed, water velocity at 200 m depth and wave height had significant effects on the depth difference between the headline and the section 3-4 net body connection(P<0.05), The depth difference between the headline and the section 3-4 net body connection increased first and then decreased with the towing speed and water velocity at 200 m, When the towing speed was 2.6 kn and the water velocity at 200 m was 0.3 kn, the depth difference between the headline and the section 3-4 net body connection was the largest, and the depth difference was the smallest when the wave height was 2 m; The catch was positively correlated with the depth difference between the headline and upper midpoint of the cod-end mouth; Warp length was the most important factor affecting the status of trawling operations, followed by towing speed, wind speed, wave height, and water flow velocity.