Abstract:The effective assessment of circuit breaker status is crucially important for developing condition maintenance. Due to faults in the existing assessment method, we develop a method based on matterelement theory to assess the condition of highvoltage circuit breakers. A method based on electrical testing, mechanical properties, appearance, working environment and maintenance condition can analyze the ascription degree of each index with relevant functions and evaluate the circuit breaker status qualitatively and quantitatively. At the same time, using the analytic hierarchy process(AHP) method to determine the constant weight of every index, we introduce a variable weight model based on a balanced function. This model considers the proportionality synthetically among every index and derives variable weights by modifying the constant weights, thereby improving assessment accuracy. The condition assessment method for highvoltage circuit breakers based on matterelement theory is shown to be effective based on experimentation with an actual circuit breaker.