The invention provides a pressure sensor and a packaging method thereof. The pressure sensor comprises a base plate and a pressure sensor chip which are arranged in a laminating manner; the pressure sensor chip comprises a substrate, a cavity formed at one side, deviating from the base plate, of the substrate, and a sensitive membrane arranged in matching with the cavity; the cavity is flat; the substrate is provided with a first bonding pad; the base plate is provided with a second bonding pad which is electrically connected to the first bonding pad; the pressure sensor further comprises a first surrounding dam which is arranged along the periphery of the sensitive membrane, a hard sealing layer which is arranged on the base plate and does not go beyond the first surrounding dam, and a pressure-bearing component which is located above the sensitive membrane and is connected with the surrounding dam in a supporting manner; and the first bonding pad is located at the outside of the first surrounding dam. By adoption of the pressure sensor and the packaging method thereof, the sensitive membrane is prevented from directly bearing an outer stress, the damage probability is reduced, meanwhile better protection is realized through the hard sealing layer, and the service lifetime is prolonged.