Aimed at the problems that the traditional rigid MIMO antennas are large in space occupation, complex in structure, and manufacturing process is tedious, two types of flexible MIMO antennas, a symmetrically arranged two-element flexible MIMO antenna and an orthogonally arranged four-element flexible MIMO antenna, are proposed in this paper. Prototypes of both antennas are successfully manufactured on a flexible PET substrate by adopting the low-cost, simple and easy-to-modify inkjet printing technology. The measured results show that the reflection coefficient of the two-element flexible MIMO antenna is a range from 2.74 to 12.47 GHz, while that of the four-element flexible MIMO antenna is a range from 2.7 to 13.4 GHz, both of which are in excellent agreement with the simulation results. For the two-element flexible MIMO antenna, the T-shaped branch structure is utilized for making its isolation meet the needs of 15 dB, while the quaternary flexible MIMO antenna achieves an isolation of greater than 20 dB through the orthogonal configuration of the ports. These antennas are characterized by a low profile, low cost, transparency, flexibility, and simple structure, along with good diversity performance, making them suitable for communication application in requiring multiple antennas.