The invention relates to a lignite drying and screening forming process which comprises the following steps of: directly sending the lignite to a rotary-cylinder drying and screening machine after processing lignite by a pulverizing machine, and drying the lignite by hot flue gas; introducing the dried lignite into a screening cylinder during lignite raw material drying process, directly delivering out the screened coarse lignite, and introducing fine lignite particles into a forming machine; introducing fine lignite powder in the rotary-cylinder drying and screening machine into a fine powder collecting device, introducing the dust in the fine powder collecting device into a cloth bag dust-removing device through a duct, and introducing the fine lignite powder into the forming machine; delivering out the fine lignite particles and the fine lignite powder after forming in the forming machine; and exhausting dust by a fan machine through a duct. The invention screens lignite during the drying process, selects high-quality lignite as a finished coal product to be sold at a high price, and forms low-quality coal as molded coal to be sold in an adhesive-free extrusion mode. The process increases the heat value of lignite, reduces the self ignition probability of lignite, and solves the problem of environmental pollution of powder coal during storage, packaging and transportation processes. By adopting the special device for drying and screening, the invention has simple process and wide application range.