The invention provides a battery pack circuit resistance monitoring device comprising an intelligent control unit, a voltage acquisition unit, a current test unit, a pure resistance load unit, a communication interface unit, a data processing unit and a fault alarm unit. The invention also provides a battery pack circuit resistance monitoring method comprising the following steps of connecting thebattery pack circuit resistance monitoring device and setting parameters; adjusting an intelligent control unit to start a battery pack circuit resistance test; analyzing the test results, and storing in a battery circuit resistance database if the test data is normal; and if the test result is abnormal, issuing an alarm message. The invention can realize the online timing test of the battery pack circuit resistance, which directly detects the resistance of the entire series circuit of the battery pack, judges the change tendency of the battery pack circuit resistance through vertical comparison of multiple measured data, and timely finds the battery pack circuit abnormality to ensure that the battery pack can supply power reliably.