In his capacity as Colonial Secretary, Norman-Walker focused primarily on social, industrial and commercial development. In 1970, accompanied by Sir Sik-nin Chau, he led a delegation representing Hong Kong to the Expo in Osaka, Japan. Norman-Walker was also an "ex officio" member of both the Executive and Legislative Councils of Hong Kong. He administered the government for several occasions on the absence of the Governor. In October 1971, he was the acting Governor who welcomed the seven-day royal visit paid by the Princess Anne.