A technical-evolution-oriented objective evaluation method of essential patents in patent pools is proposed, aiming to overcome the defects caused by the current method hiring of third-party experts to identify and evaluate essential patents subjectively. Following the Mendel’s genetic law, the origin and evolution of technology are traced with the method of technological genetic decomposition. The concept of technological adaptation index is put forward to measure adaptabilities of patents in technological evolutions. The adaptive patents with high technological adaptation index are strictly screened and filtered combining with technical standards as candidates of essential patents. The essentials of patents in patent pools are ensured and the "win-win" development of patentees and technology fields is guaranteed. Through an empirical analysis, adaptive patents in technological evolutions of the fuel cell are evaluated. Results show that, these adaptive patents demonstrate technological developments of the fuel cell both from the perspectives of patent citations and patent contents. It is consistent with the central idea of essential patent evaluation: technological evolution. And these adaptive patents contain some technological elements, which are important means and technical support of functional indexes or performance requirements specified in fuel cell related technical standards. So these adaptive patents should be essential patents that are unavoidable.