The invention discloses a device for detecting polymer confecting conditions on site. The device for detecting the polymer confecting conditions on site comprises a Christmas tree of a polymer injection well, a flow distributor and a polymer confecting device. The polymer injection well is provided with a first production valve and a casing valve; the flow distributor is connected with the Christmas tree; a liquid inlet hole of the polymer confecting device is connected with the first production valve, and a liquid outlet hole of the polymer confecting device is connected with the casing valve. The polymer confecting device comprises a shell and an adjustable flow core; the shell comprises an intermediate sleeve, a first shell and a second shell, wherein the first shell is connected with the first end of the intermediate sleeve and is provided with a liquid inlet hole and a first pressure measuring opening for installing a first pressure gauge, and the second shell is connected with the second end of the intermediate sleeve and is provided with a liquid outlet hole and a second pressure measuring opening for installing a second pressure gauge; and the adjustable flow core comprisesa core bar, a guide rod and a throttling core bar, the core bar passes through the first shell and can rotate relative to the first shell, the guide rod is fixed on the second shell and is provided with a guide rail in the axial direction of the guide rod, and the throttling core bar is arranged on the core bar in a sleeved mode and located in the intermediate sleeve and can move into the secondshell along the guide rail. Detection results of the device for detecting the polymer confecting conditions on site is reliable and high in accuracy.