Factors such as optical noise and electronic device noise can affect the accuracy of the strain field in the digital image correlation method. This paper introduces an algorithm based on single-point redundant strain information. This algorithm suppresses noise in the strain field through weighted summation using a probability density function or constructing an exponential weight function. In the pointwise least squares method, this proposed algorithm is used to identify the strain field of the computed-simulated speckle images test, the tensile test of a plate with one hole, and the bending test of a reinforced concrete column with cracks. The results show that in the case of homogeneous deformation, compared with the classical pointwise least squares algorithm, the accuracy of the strain field calculated by the proposed method has been effectively improved; while both methods achieve the same precision, the calculation speed of the proposed method by more than 65%. Moreover, the proposed method can obtain more reliable strain values in the region near the crack, giving it a broader range of application. Furthermore, compared the regularization-aided finite element strain calculation method, the proposed method has greater accuracy and a faster calculation speed.