Lipase is a kind of industrial enzyme preparation with various catalytic abilities and is widely used in food, energy, medicine and other fields. To increase lipase and enzyme cocktail activity through solid-state fermentation, the novel strain Penicillium sp. Y-21 was obtained through ethyl methanesulfonate (EMS) mutation from the novel strain Y, which was isolated from soils. Solid-state fermentation by strain Y-21 using agricultural byproducts was carried out in tray bioreactors. The optimum culture composition for enzyme cocktail fermentation was soybean meal 20 g, 3% (w/w) glucose, 1% (w/w) peptone, 5% (w/w) lard, 0.04% (w/w) CaCl₂, 0.04% (w/w) FeCl₃, 28 °C for 72 h. The enzyme cocktail produced by strain Y-21 is a kind of multienzyme complex, containing xylanase, glucanase, acidic protease, pectinase, cellulase and lipase, and their enzymatic activities (unit: U g⁻¹) were 8000, 6000, 8000, 2000, 3000 and 120, respectively. During the fermentation process, the lipase coding genes pel, pha, and p12 were also studied and amplified from the RNA of Penicillium sp. Y-21 by RT-PCR. The results showed that the pel gene played an important role in enzyme production. Afterwards, an enzyme cocktail can be added to chicken feed as an additive, which improves animal growth and feed efficiency.