The invention relates to a device for measuring the distribution density of flowing foams in core. The device comprises a foam injection system, a core displacement system, a pressure measurement system, a computer, a constant-temperature tank and a foam scanner, wherein the foam injection system is used for providing a fluid condition for a foam flooding simulation experiment; the core displacement system is used for simulating a seepage process of the porous medium foam flooding; the pressure measurement system is used for monitoring the pressure of different positions in real time; the constant-temperature tank is used for simulating the temperature condition of the stratum; and the foam scanner is used for measuring the distribution density of flowing foams in core. The device is adopted to measure the distribution density of flowing foams in core independently; the device has strong practicability, can quantitatively describe the foam distribution density on the basis of foam acquisition and scanning, and the device can provide technical support for researching the migration law of the foams in porous medium.