The invention provides an olfactory analog instrument and an on-site analysis method for the odor grade of a specific substance. The invention has the following characteristics: 1, a gas sensor array constant temperature operation room, a computer and an autoinjection system are integrated in a test box; 2, utilization of a sample bottle with a volume of 250 ml and 25 ml of a to-be-tested sample enables a gas-liquid ratio to be 9: 1; 3, parallel resistance wires respectively wind in a semi-circle manner to generate 45-W power, so the sample and headspace volatilized gas are heated to a temperature of 80 DEG C in only 8 min and maintained at the temperature for 30 min; 4, 25 ml of an aqueous ethanol solution with a concentration of 100 ppm is used to generate standard reference gas in the sample bottle with a volume of 250 ml, and correction on gas sensors are carried out based on the generated standard reference gas; 5, headspace sampling flow is 500 ml / min, sampling time is 30 s, and gas sensor response signals undergo lowpass filtering and dimensionality reduction pretreatment; and 6, a database is established, and the olfactory analog instrument carries out on-site detection and grade prediction and identification on the odor of specific substances consisting of an adhesive, petroleum wax, leather, glycerin and edible vegetable oil.