Walker received his Ph.D. from Oxford University in 1969, and then undertook research projects in universities in the United States and Paris. His award-winning research was conducted in the molecular biology laboratory of the Medical Research Council of Cambridge University. 1974 entered the laboratory, and 1982 became a senior chemist. In the early 1980s, Walker began to study adenosine triphosphate synthase, the main productive molecule of most organisms, which was helpful to the synthesis of adenosine triphosphate, a chemical energy carrier. The research focuses on the chemical composition and structure of enzymes. He determined the amino acid sequence that constitutes the protein unit of synthetase. In 1990s, Walker cooperated with X-ray crystallographers to clarify the three-dimensional structure of enzymes. His research supports Boyer's "binding transformation mechanism" (an unusual way to explain the characteristics of enzymes). Walker's discovery provides insights into the way organisms produce energy.