The utility model discloses a cased well stratum dynamic monitoring device, include malong head, electron festival, balanced festival, hydraulic pressure festival, seal and save and the cable at a distance from festival, suction inlet, cable, malong head, electronics festival, balanced festival, hydraulic pressure festival, seal and separate festival and suction inlet festival from last to arranging in proper order down, the malong head including casing, an electric connector, piston, prevent rotary drum, shearing pin and cable sheathing, the balanced festival includes the 2nd electric connector, the 2nd pressurization head, joint, dummy piston, interior casing and shell body. The device carries out once stratum parameters such as miniaturized stratum fluid " exploitation ", exploitation process monitoring profit proportion, temperature, pressure in the pit, confirm the remaining oil saturation and the stratum water logging degree on stratum to find valuable mined bed according to stratum indexs such as output, exploitation time, temperature, and the device can once measure a plurality of levels, and direct measurement stratum fluid properties matter is the dynamic testing under " exploitation produce " on a small scale state.