The embodiments of the present invention disclose a preparation method for a sensor encapsulation structure and a sensor encapsulation structure. The preparation method for the sensor encapsulation structure comprises the following steps that: a chip is provided, and a functional circuit is formed on the first surface of the chip; balls are formed on the second surface of the chip which is opposite to the first surface, the balls are electrically connected with the functional circuit; the first surface of the chip is attached to the first surface of a protective portion; an encapsulation layer is formed above the first surface of the protective portion, and the encapsulation layer wraps the chip; and the encapsulation layer which is far away from the first surface of the protective portion and the balls are thinned, so that pads can be formed, and the formed pads are exposed regions of the balls. With the preparation method provided by the embodiments of the present invention adopted, technical difficulty can be decreased, the problem of the scrapping of a sensor encapsulation structure due to flash of open molding can be solved, and sensor encapsulation yield can be improved.