Tricresyl phosphate (TCP) is a class of neurotoxic organophosphate cholinesterase inhibitors, exposure to which may induce nausea, vomiting, diarrhea and abdominal pain. Despite of its acute toxicity, TCP is widely used in industrial applications, including flame retardants, and plasticizers. Many military and commercial aircrafts have employed hydraulic fluids containing TCP organophosphates additive since the 1970s. Potentially TCP could be released into the cabin air environment during oil leakage on aircraft hydraulic systems. Exposure to passengers and crew occurs mainly through ingestion, inhalation of aerosols, and dermal sorption. In this study, an automatic electrochemical detection system was developed to measure the TCP in gas. TCP was absorbed and hydrolyzed by an alkaline alumina column, to obtain hydrolysates that are electrochemically active, i.e. cresol, and then washed out by buffer for direct electrochemical detection. After each detection, NaOH solution was used to regenerate the column. The effects of different experiment conditions were investigated such as elution time, alumina type, the composition of regeneration solution, flow rate, temperature, etc. Through the optimization, an automatic TCP detection device was obtained with features of high sensitivity, regeneration capability and portability, which could be utilized in site test of cabin.