Three-dimensional sand architecture modeling is an important method to characterize the spatial distribution of sands with different microfacies, which is of great significance for accurately predicting the distribution pattern of residual oil and improving oil and gas recovery. The existing three-dimensional architecture modeling methods mainly characterize the spatial structure of the geologic body through variograms, geometric parameters, training images, etc., which often fail to adequately represent the spatial distribution of the sand body in the case of diverse microfacies and complex distribution, making it difficult for the existing modeling methods to effectively depict the complex distribution of the sand body under the condition of the well data. Therefore, this paper introduces the existing understanding of planar microfacies distribution into the three-dimensional sand architecture modeling process based on one-dimensional well data, and proposes a three-dimensional sand architecture modeling method based on planar facies constraints. The method takes different microfacies of single sand body as the modeling target, introduces the planar constraint on the planar distribution region and morphological characteristics of each single sand body, and establishes the 3D sand body architecture model by determining the microstructural surfaces of the top and bottom of the sand body within the planar distribution region. In addition, in order to effectively portray the profile morphology of the sand body, a mathematical model is used to optimize the microstructural surfaces of the single sand body, and the superposition relationship is used to optimize the contact relationship between the sand bodies. The results of modeling application in a block of Shengtuo oilfield show that this method can well characterize single sand bodies of different microfacies, and has more advantages than the existing methods in portraying the complex morphological features of sand bodies.