The invention discloses a wafer-level antenna packaging structure and a preparation method thereof. The packaging structure comprises a first antenna structure, a first conductive structure, a first plastic packaging layer, a second antenna structure, a second conductive structure, a second plastic packaging layer, a chip, a third plastic packaging layer, a third conductive structure, and a re-wiring layer; the first conductive structure is arranged on the first antenna structure and is electrically connected with the first antenna structure; the first plastic packaging layer plastically packages the first antenna structure and the first conductive structure; the second antenna structure is formed on the first plastic packaging layer; the second conductive structure is arranged on the second antenna structure and is electrically connected with the first antenna structure; the second plastic packaging layer plastically packages the preset edge area of the second antenna structure and the second conductive structure with a cavity reserved; the chip is arranged on the second plastic packaging layer and seals the cavity; the chip is plastically packaged by the third plastic packaging layer; the third conductive structure penetrates through the third plastic packaging layer and is electrically connected with the second conductive structure; and the re-wiring layer is formed on the third plastic packaging layer and is electrically connected with the third conductive structure and the function leading-out end of the chip. According to the wafer-level antenna packaging structure and the preparation method thereof of the invention, the antenna and the chip are integrated and packaged; and therefore, the packaging structure is small in size, cost can be saved, and at the same time, the signal receiving and transmitting performance of an antenna is improved.