The invention discloses a method for acquiring the oil-and-gas-containing probability of a trap. The method comprises a step 1 of defining a factor of the oil-and-gas-containing probability of the trap on the basis of a trap reservoir-forming essence; a step 2 of constructing a parameter system of the oil-and-gas-containing probability according to the actual geological condition of the trap; a step 3 of assigning a value to the factor on the basis of the parameter system; and a step 4 of computing the oil-and-gas-containing probability of the trap according to the value of the factor. The method may carry out a united quantitative analysis on the oil-and-gas-containing properties of traps in different fields and different regions, reduces the influences of subjective human factors in an oil-and-gas-containing probability acquisition process to the utmost extent, and achieves a result more according with a reality.