The coronavirus pandemic corresponds to a serious global health crisis which not only changed the way people used to live but also how people behaved in their daily lives. Information from social and behavioural sciences can help in modifying human behaviour to comply with the recommendations of health officials, as the pandemic requires large-scale behaviour change and puts significant mental stress on individuals. The aim of this paper is to examine the changes in human behaviour brought about by the COVID-19 pandemic, which has caused a global health crisis and altered the way people live and interact. The collection of data has been done through online mode and the behaviour of the people is observed, and the results were finally analysed using the Analytical Hierarchy Process (AHP) which is a multi-criteria decision-making method to rank the factors that had the greatest impact on the changes in human behaviour. During the study, parameters taken under consideration were the ones which were most likely to affect the human behaviour as an impact of COVID-19 lockdown on health, relationship with family and friends, overall lifestyle, online education and work from home, screen time etc. The paper explains each criterion and how it affected human behaviour the most.