The invention discloses a detection method for determining an optimal inflation recovery factor beta of a flotation machine. The method comprises the steps that an inflation recovery factor beta on-line collecting device is arranged on the flotation machine and used for collecting the foam overflow flow velocity, foam overflow height and foam color component value of the flotation machine, and according to the foam flow velocity, the foam overflow height and the inflation quantity of the flotation machine, the inflation recovery factor beta is calculated, wherein the inflation recovery factor is shown in the description, Vf is the foam flow velocity, H is the foam overflow height, L is the overflow weir length, and Qa is the inflation quantity of the flotation machine; after the inflation recovery factor beta is detected and calculated, the mean values of the inflation recovery factor beta and the foam color component values in adjacent time periods are compared, the adjusting direction and adjusting step of a set value of the inflation quantity are determined, an allowable adjusting interval of the inflation quantity is set, and then traversal is conducted within the allowable adjusting interval to find out the maximum value of the inflation recovery factor beta as an optimal value. According to the detection method for determining the optimal inflation recovery factor beta of the flotation machine, the flotation machine can be automatically adjusted to be in the state of the optimal inflation quantity.