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• A modified contact detection judgment in MPM for coining process is proposed. • The improved method overcomes small time step and abnormal termination of simulation. • The proposed method avoids virtual contact distance and obtains fine patterns. • The novel method reduces amount of data storage and computations. • Predicted insufficient filling agrees well with experimental result. [Display omitted] Extremely small time step caused by large deformation in coining process significantly increases computational time in dynamic explicit finite element method (FEM). Furthermore, negative volumes of distortion elements in the rim of coin lead to abnormal termination of simulation. In order to overcome these problems, dynamic explicit material point method (MPM) is employed for coining process. However, most of the point-to-point contact algorithms in MPM cause fake contacting detection. In addition, abundant tiny patterns on die surfaces put forward high requirement for the contact algorithm to calculate the normal vectors. A point-to-segment based contact algorithm is proposed to obtain accurate normal vectors at real physical contact point and embedded into the framework of modified update stress last (MUSL) for simulating coining. Amount of data storage and computations are reduced since the background domain only contains the deformable workpiece and one velocity field is required. The improved MPM is applied to predict insufficient filling during minting, and its performance is validated by experimental results. [ABSTRACT FROM AUTHOR]