Ultrasonic sensing appratus

An ultrasonic sensing apparatus includes an accommodating shell and at least one detection device. The accommodating shell includes a base and a convex portion connected to the base, the base has a first detection opening toward a first direction on a side thereof, and the convex portion has a second detection opening toward a second direction on a side thereof. Each detection device includes a board, a piezoelectric assembly, a housing and a plurality of fixing members. The board is disposed in the accommodating shell and covers the first detection opening or the second detection opening. The piezoelectric assembly includes an encapsulation body disposed on the board and a piezoelectric sheet covered by the encapsulation body, the piezoelectric sheet has a sensing surface exposed from the encapsulation body and far away the board. The housing includes a bottom wall exposed from the first surface or the second surface, a top wall disposed on the board and a surrounding wall connected between the bottom wall a