Abstract: China has a large area of sewage irrigation farmland which has partly caused heavy metal pollution, especially cadmium pollution. Aimed to understand the present advances of soil cadmium pollution in sewage irrigated farmland, based on the results of literature analysis software, the research progress at home and abroad from the overall perspective of soil-crop ecosystem has been summarized; the content characteristics, transport mechanism and pollution remediation of heavy metal of cadmium pollution in soil-crop ecosystem of sewage irrigated farmland have been reviewed. Highlights show that the cadmium in sewage irrigated farmland soil has the character of surface aggregation, but long-term sewage irrigation may lead to the migration of heavy metals to deeper soil layers. The enrichment degree of cadmium is different in different organs of the same crop and different crops, and there was no significant correlation between cadmium content in soil and crops in field experiment, so that it is urgent to carry out researches on safe utilization of farmland. Although several mathematical models have been used in the study of heavy metal cadmium transport in soil-crop ecosystem, a systematic and widely used model has not yet been formed due to the different conditions of irrigation time, irrigation amount and irrigation frequency. The prominent problems in the study on heavy metal cadmium in sewage irrigation farmland include unclear vertical distribution of cadmium pollution, unclear morphological changes during soil to crop migration, immature practical remediation technology, etc. In the future, researches should be focued on the quantification of the influencing factors of heavy metal cadmium accumulation in farmland soil-crop ecosystem, strengthening of investigation and monitoring of heavy metal cadmium in farmland deep soil, and exploring technologies for remediation and safe utilization of cadmium polluted sewage irrigated farmland.