The invention relates to a sampling 
resistor sensor for the extra-high-
voltage direct 
corona current. The sampling 
resistor sensor comprises a cylinder-shaped sampling 
resistor, wherein an insulation tube penetrates through the hollow part of the sampling resistor, each end of the insulation tube is fixedly connected with an insulation 
flange plate, two grading rings are respectively fixed on the two insulation 
flange plates through 
metal flange plates arranged at the centers of the two grading rings, one end of one 
metal flange plate is connected into an extra-high-
voltage transmission line through a screened lead, the 
corona current of the extra-high-
voltage transmission line is required to be measured, the other end of the 
metal flange plate is connected with one end of the sampling resistor through the screened lead, the other end of the sampling resistor is connected with the other metal flange plate through a screened lead, the sampling resistor is connected with a shunt resistor in parallel through a screened lead, and the shunt resistor is arranged in the insulation tube. The sampling resistor sensor can be widely used in the 
direct current extra-high-voltage environment with plus or minus 1200 KV (kilovolt) to the largest extent and realizes the wide-frequency-domain accurate measurement of the 
corona current in the extra-high-voltage 
transmission line.