The article introduces AutoThink, an innovative approach designed to enhance the inference efficiency and accuracy of reasoning Large Language Models (LLMs). AutoThink addresses the challenge of LLMs generating excessive or insufficient reasoning tokens, which leads to computational inefficiency and suboptimal performance. This system comprises two main components: a query complexity classifier that dynamically allocates the optimal number of reasoning tokens, and a dataset of control vectors derived from "pivotal tokens" to guide the LLM's reasoning path. Experimental results demonstrate that AutoThink significantly reduces output tokens while substantially improving accuracy on complex reasoning tasks, suggesting a more strategic approach to LLM resource allocation rather than simply increasing computation.