The novel coronavirus disease 2019 (COVID-19) has placed tremendous pressure on public health systems across the world. Compared with the healthy population, cancer patients are more prone to developing psychological problems, including depression and anxiety, because of worries about cancer recurrence, cancer symptoms, treatment-related discomfort, a lack of social interaction and the impact on their financial well-being. This paper aimed to identify existing evidence on psychological symptoms and their associated factors among cancer patients in the Chinese Mainland during the COVID-19 pandemic, and on interventions to effectively manage these symptoms. Articles related to the prevalence, the risk factors and interventions of psychological symptoms among cancer patients in the Chinese Mainland during COVID-19 published between December 2019 and August 2020 were searched in two English (PubMed and Embase) and two Chinese (CNKI and Wan Fang Data) databases. A total of 180 studies were identified, and 18 studies were included in the review after removing duplicates and screening for relevancy. The results suggest that patients with cancer in the Chinese Mainland have suffered psychological pressure during COVID-19, with a high prevalence of psychological distress, depression and anxiety reported across most of the reviewed studies. Pandemic-related factors such as treatment discontinuation and worry about being infected are associated with these symptoms. Nurses may help to relieve these symptoms by identifying stressors, providing relevant information through mass and social media and referring patients to specialists for psychological support. However, evidence about treatments and interventions for these symptoms is limited, and additional research is warranted to identify effective interventions to promote resilience in this patient population.