Multi-turn conversational systems based on large language models are increasingly being integrated into web platforms and applied across a wide range of domains. However, these systems typically combine the userߣs current query with contextual information from previous interactions, resulting in continuously expanding input prompts. This leads to a significant increase in time-to-first-token (TTFT), causing intolerable delays in web response times. To address this issue, we introduce TransformKV, which maximizes the reuse of the KV cache from previous conversations rather than recomputing, thereby reducing TTFT latency. TransformKV first identifies the specific locations that require transformation to maximize the reuse of the KV cache with minimal operations. It then efficiently transforms the KV cache for a subset of tokens by recomputing only the KV cache that impact semantics. Additionally, TransformKV further reduces TTFT latency by performing only QKV computations in certain layers while skipping other computations that contribute less to overall performance. Experimental results demonstrate that in multi-turn conversation tasks, TransformKV can reduce inference latency by up to 30%, achieving up to a 1.8× improvement in performance compared to similar approaches. Notably, as the context window size increases, the performance gains become even more pronounced.