Academician ZHANG Huanqiao is an outstanding scientist cultivated by the new China in the 1950s. The impoverished and weak war environment of the old China and the hardship era of the new China have nurtured his patriotic determination to serve his motherland. He adhered to the frontline of scientific research and devoted himself wholeheartedly to it. His research fields spanned neutron physics, fission physics and heavy-ion nuclear physics, and he has achieved excellent results under difficult conditions. He committed himself to the country and measured the urgently needed nuclear data to cooperate with nuclear weapon development. He is rigorous and realistic, and repeatedly verifies the experimental results to ensure accuracy. He dares to take the lead and constantly delves into new research fields. All his actions reflect a silent loyalty and love for his motherland and science. He is an inheritor and speaker of the older generation scientists' spirit, and a microcosm of the scientist's spirit and the development of science and technology in the new China. We write this article for sharing on the occasion of academician ZHANG Huanqiao's 90th birthday.