We undertook this study in order to explore the impact of stationary magnetic field (SMF) and alternating magnetic field (AMF) treatments at different intensities (1.5 and 4.5 mT) combined with freezing and/or thawing on the water retention and quality of precooked meat patties. The results showed that magnetic field-assisted freezing shortened the time required to pass through the maximum ice crystal formation zone, thereby accelerating the freezing rate. In addition, it reduced the thawing rate, thawing loss and cooking loss, decreased the proportion of free water, increased the proportion of immobilized water, and improved the hardness, elasticity, cohesiveness and chewiness of meat patties (P < 0.05). The 4.5 mT AMF treatment shortened the time required to pass through the maximum ice crystal formation zone by 417 min compared with the control group, and thawing loss and cooking loss decreased by 59.62% and 58.07% in the AMF-assisted freezing-thawing group, respectively. Furthermore, the hardness, elasticity, cohesiveness and resilience were significantly higher than those of the control group (P < 0.01). In summary, magnetic field-assisted processing holds potential in the freezing and thawing of prepared meat products.