A stress sensor includes a circuit board having a stress sensitive structure, a pointing stick and a metallic back plate. The stress sensitive structure includes a stress deformation region and multiple resistors located on the stress deformation region. The pointing stick is disposed on a top of the circuit board and connected to the stress sensitive structure. The metallic back plate includes at least one fixing material coating region, and thus the fixing edges of the circuit board are fixed on the corresponding fixing material coating region. An assembly method for the stress sensor is also provided.