The invention relates to a dynamic synchronous distributor of a hydraulic oil cylinder, which comprises a main oil cylinder and a plurality of sub oil cylinder groups corresponding to the number of external work oil cylinders, wherein each sub oil cylinder group comprises n sub oil cylinders, wherein n is larger than or equal to 2; the size of the oil cylinder meets the following requirements: the sum of the single stroke flow rate of n sub oil cylinders in one group is the same as the single stroke flow rate of corresponding external work oil cylinders; plunger pistons of the main oil cylinder are connected with plunger pistons of each sub oil cylinder, and can move synchronously with the plunger pistons of each sub oil cylinder; a hydraulic oil connecting pipe of the main oil cylinder is connected with an oil path of a hydraulic motive power cabinet; and the hydraulic oil connecting pipes of all sub oil cylinders in the same group are connected with a chamber at one end of the corresponding external work oil cylinders. The distributor of the invention is used for distributing the hydraulic oil of a plurality of hydraulic oil cylinders in cooperative work, and can ensure that a plurality of external hydraulic oil cylinders in cooperative work can reach completely identical dynamic synchronous requirements at the time in the whole work process. The whole distributor operates stably, and has simple structure and reliable operation.