An analytical model for the large-core optical fiber connector is presented based on beam propagation method(BPM). In the case of the linear and nonlinear (including sinusoidal and cosine) vertical section of connector, affections of the coupling length and coupling angle for the connector on the insert loss and coupling efficiency are discussed when the beginning section and the ending section act as the input respectively. Optimum vertical section, length, and angle of the connector are obtained.