The stability and activity of enzymes are the main bottlenecks in enzyme's industrial applications. Therefore, engineering enzymes for improved catalytic performance is an important topic for industrial biocatalysis in the current status. In this work, hydrophobic monomers, isobutyl methacrylate (IBMA) and ethyl methacrylate (EMA) were grafted onto surface of Candida rugosa lipase (CRL) via atom transfer radical polymerization (ATRP), respectively, to synthesize two hydrophobic polymer-grafted lipases, pIBMA-g-CRL and pEMA-g-CRL. Compared with wide-type CRL, the catalytic activity and stability of pIBMA-g-CRL and pEMA-g-CRL improved significantly. After grafting with hydrophobic polymers, Michaelis parameter of CRL decreased from 9.98 mmol/L to 6.91 mmol/L (for pIBMA-g-CRL) and 8.54 mmol/L (for pEMA-g-CRL), whereas turnover number increased from 5.63 to 16.97 (for pIBMA-g-CRL) and 22.36 (for pEMA-g-CRL). As a result, catalytic efficiency of pIBMA-g-CRL and pEMA-g-CRL was 4.39 times and 4.68 times as high as that of wide-type CRL, respectively. Moreover, pEMA-g-CRL retained 92% activity after incubating at 50℃ for 6 h. It reflected that hydrophobic polymer grafting induced the opening of lipase "lid" structure and led to exposure of catalytic active site. Meanwhile, lipase in lid opening conformation had better stability. Spectroscopy experiments further confirmed that the improvement of lipase catalytic performance was closely related to the change in secondary and tertiary structure of lipase. CD results showed a decreased content of α-helix and an increased content of β-sheet in hydrophobic polymer-grafted CRLs. Moreover, as shown by fluorescence emission spectra, a blue shift of hydrophobic polymer-grafted CRLs was observed, which indicated a more compact structure than wild-type lipase. The results in this research demonstrated that IBMA and EMA, as the monomers for grafting CRL, had a significant improvement to the stability and activity of CRL, and the resulting polymer was a potential material for lipase modification.