The recent transition in the software industry toward dynamically generated code poses a new challenge to existing dynamic binary translation (DBT) systems. A significant re-translation overhead could be introduced due to the maintenance of the consistency between the dynamically-generated guest code and the corresponding translated host code. To address this issue, this paper presents a novel approach to optimize DBT systems for guest applications with dynamically-generated code. The proposed approach can maximize the reuse of previously translated host code to mitigate the re-translation overhead. A prototype based on such an approach has been implemented on an existing DBT system HQEMU. Experimental results on a set of JavaScript applications show that it can achieve a 1.24X performance speedup on average compared to the original HQEMU.