The invention relates to a twinkled activity indicator belonging to the field of nuclear technique applications and measuring instruments. The activity indicator contains a probe bracket, the partial pressure resistance is mounted on the bracket, and the photomultiplier is mounted on the partial pressure resistance, the scintillator is mounted on the photomultiplier, under the bracket there are signal output connections which connect with the anode of photomultiplier and high pressure connections which connect with photomultiplier via the partial pressure resistance. Because the detecting head is scintillation crystal not the ionization chamber with thick wall, the energy-limiting valve of testing nuclide and the work voltage can be dropped, the alpha, beta charged particles can be detected, and the efficiency of detecting the low energy photon nuclide can be improved. Because of the photomultiplier, the pulsing signals can be measured, and the sensibility of the detecting head can be improved. According to the kinds of the nuclides, you can choose detector with different crystals that it can drop the cost, and it is economic and practical for medium-sized, pint-sized or county hospitals.