An adjustable head-mounted structure comprises overlapping and staggered first and second head strips, one end of each respectively arranged in a groove shaped bracket, the first head strip connected with the bracket. A sliding cavity extending along the first head strip is provided on an end thereof. Limiting slots are provided at lateral intervals of the sliding cavity. An elastic piece is connected with the second head strip having connecting and bending portions in an end notch of the second head strip. The bending, portion is inserted into the sliding cavity and clamped into a limiting slot. A through hole extending along the bracket is provided on a sidewall close to the limiting slot. A button in the bracket has a pressing portion to be inserted into the through hole and connected to a baffle plate, with a fixed connection structure between the baffle plate and the second head strip.