Direct-current sampling method in wide-temperature environment

The invention discloses a direct-current sampling method in a wide-temperature environment. The direct-current sampling method includes that under the condition of not increasing hardware cost and selecting to use a non-wide-temperature A/D (analog to digital) acquisition device, and acquired data is compared with standard data to obtain an actual state quantity in current environment temperature, so that degree of accuracy of state monitoring of a transformer is increased. A standard signal resource refers to physical quantity acquired by a corresponding sensor, corresponding relation of temperature, accurate state quantity and pre-acquired data is obtained by monitoring the standard signal source in advance, than actual monitored data are substituted into the corresponding relation to be compared to obtain the accurate state quantity, and the state quantity is taken as actual output. To-be-monitored state quantity can be acquired on the basis of not updating devices, so that cost is lowered.