Control method for separating cyclopentadiene from C5 fraction by utilizing dimerization method

The invention discloses a control method for separating cyclopentadiene from a C5 fraction by utilizing a dimerization method. The method makes the loss of cyclopentadiene and the content of cyclopentadiene in the outlet be the least through controlling the reactor temperature, and comprises the following steps: establishing an objective function and function expressions of each variant in the objective function so as to calculate the optimal value of reaction temperature T; and substituting the optimal value into each control circuit to achieve the goal of controlling the reaction temperature. The method makes the loss of cyclopentadiene and the content of cyclopentadiene in the outlet be the least, thus maximally recycles cyclopentadiene to make the content of cyclopentadiene reach the tolerant range of the extraction and rectification system, so that the product yield is increased and the cost is reduced.