The utility model discloses an angle-adjustable lamp base structure. The lamp base structure comprises a light source and a baffle plate; the light source is fixed at the bottom of the baffle plate; the lamp base structure also comprises a strut and a connecting plate; the bottom of the strut is fixed on a lamp post; the top of the strut is in arc shape; furthermore, the upper part of the arc is provided with an auxiliary hole and at least two positioning holes; the bottom of the connecting plate is provided with an arc-shaped trough that can contain the top of the strut; furthermore, two ends of the arc-shaped trough, corresponding to the strut, are fixed with a fixed sheet respectively; the fixed sheet is also provided with a chute corresponding to the auxiliary hole and through holes corresponding to different positioning holes; and the fixed sheet is fixedly locked with the corresponding auxiliary hole or positioning hole by a locking fastener. The lamp base structure leads the lighting angle of the light source to be easy to be adjusted and has simple structure.