Micro-, and milli-scale robots have emerged as next generation of intelligent technology for minimally invasive diagnosis and treatment. Recent minimally invasive interventions call for robots that work as tiny “surgeons” or drug delivery “vehicles” to achieve inner body diagnostic, surgical, and therapeutic practices, without any trauma or discomfort. Most traditional medical robots are large, and lack effective locomotion design, which prevent them from entering small entrances and moving smoothly in small working areas, such as long and narrow passages. Presented in this paper is a design of an innovative milli-scale deployable tensegrity microrobot for minimally invasive interventions. The robot is made of a deployable tensegrity structure integrated by self-stress. A folded size of the robot is small for easily entering a desired working area with a small entrance. When deployed, the tensegrity body of the robot displays lightweight and high stiffness to sustain loads and prevent damages when burrowing through tightly packed tissues or high-pressure environments. Locomotion of the tensegrity microrobot is designed to mimic a crawling motion of an earthworm, which grants the robot an ability to move well through small working areas. The robot is also an untethered agent. Morphing for deployment and locomotion of the robot is actuated by magnetic forces generated by its active members that serve as electromagnetic coils.