Abstract: Covalent organic frameworks (COF) is crystalline organic polymers with periodic architectures and well-defined pores, enabling various applications such as gas storage and separation, catalysis, sensor and energy storage. Crystallinity and porosity are two important properties that determine the performance of COF, and the preparation of COF with high crystallinity and specific surface area has been a key issue in the synthesis of COF. Herein, a novel methylated covalent organic framework material (COF-946) was constructed using 2,4,6-trimethyl-benzene-1,3,5-tricarbaldehyde and 2,5-dimethyl-p-phenylene diamine as building blocks. The methylation not only significantly enhances the crystallinity and porosity by preventing pore collapse, but also allows COF-946 to be prepared in a variety of solvent systems. The basic structure and properties of COF-946 were characterized using Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results show that COF-946 with high crystallinity and specific surface area can be prepared in a wide range of solvents and within a short period of time (S_BET > 700 m²/g in 0.5 h). In addition, COF-946 has a high iodine vapor adsorption capacity (5.65 g/g) and adsorption rate (0.78 g/(g·h)), and can maintain more than 90% of the original adsorption capacity after five cycles.