The invention discloses a cavity type semiconductor electric control quantum dot device, and a preparation and application method of the same. The cavity type semiconductor electric control quantum dot device includes a non-doped GaAs substrate (101), a non-doped AlGaAs layer (102), a surface non-doped GaAs cap layer (103), an ohmic contact source electrode (201), an ohmic contact drain electrode (204), at least two quantum dot small electrodes (402), an insulating layer (500) and a gate nano strip (602), wherein the ohmic contact source electrode (201) and the ohmic contact drain electrode (204) successively penetrate through the surface non-doped GaAs cap layer (103) and the non-doped AlGaAs layer (102), and then enter the non-doped GaAs substrate (101) at least 5nm; the at least two quantum dot small electrodes (402) are arranged between the ohmic contact source electrode (201) and the ohmic contact drain electrode (204), and is arranged on the surface non-doped GaAs cap layer (103); the at least one part of the surface non-doped GaAs cap layer (103), the two quantum dot small electrodes (402), the ohmic contact source electrode (201) and the ohmic contact drain electrode (204) is covered with the insulating layer (500); and the gate nano strip (602) is arranged on the insulating layer (500), and the horizontal projection of the gate nano strip (602) are overlapped with the ohmic contact source electrode (201), the ohmic contact drain electrode (204) and the two quantum dot small electrodes (402). The invention also discloses a quantum point apparatus.