The Ordovician Wulalike Formation in the northwestern margin of the Ordos Basin is a new prospect for exploring shale gas in the North China plate. Its accumulation conditions and enrichment characteristics are quite different from that of marine shale gas fields in South China. Based on geological data such as drilling cores, logging, laboratory analysis and testing, focusing on the fracture characteristics of the Wulalike Formation, this article explores the accumulation model of marine shale gas in the northwestern margin and obtain four conclusions: (1) The Wulalike Formation, under the control of various sedimentary microfacies, develops siliceous shale, calcareous-siliceous and argillaceous-siliceous mixed shale, localized carbonate rocks (mainly brecciated limestone and marl) and calcareous shale, with large variations in lithofacies combinations in different blocks. However, the lower interval is generally rich in siliceous and exhibits similar brittleness to the lower interval of the Longmaxi Formation, which is beneficial for reservoir fracturing in the foreland thrust belt distribution zone. (2) The Wulalike Formation develops two generations of fractures: high-angle filled fractures and low-angle bedding fractures. Whilst the predominant type is the open bedding microfractures, which is more developed in the southern block compared to the northern block. (3) The lower interval of the Wulalike Formation generally has a total porosity between 2.46%-7.08%, similar to the Longmaxi Formation in the Sichuan basin, with matrix porosity accounting for 34.0%-90.0% (average 61.1%) and fracture porosity 10.0%-66.0% (average 38.9%). (4) Natural gas is mainly stored as free gas (accounting for over 64%), where primary and secondary intralayer migration occurs in inorganic pores and bedding fracture system. According to comprehensive analysis, the Majiatan-Shanghaimiao exploration area is mainly a fractured shale gas accumulation area controlled by structures. The fracture development period is synchronized with the peak gas generation period, which is conducive to the efficient accumulation of natural gas in the Wulalike Formation. The Tiekesumiao Block is a mixed shale gas reservoir.