Folding crib frame of baby crib

The invention discloses a folding crib frame of a baby crib. The folding crib frame of the baby crib comprises a lifting and pulling device with four sets of racks, the lifting and pulling device is arranged at the bottom of a supporting frame assembly, and the supporting frame assembly comprises side supporting units and upper supporting units. Linkage devices are arranged between the side supporting units and the lifting and pulling device, and each linkage device comprises a first linkage component and a second linkage component. The first linkage components are controlled by the lifting and pulling device, the second linkage components and the first linkage components are in synchronous linkage, and each second linkage component is arranged on the corresponding side supporting unit, hinged to two adjacent upper supporting units and used for abutting against, bending and folding the upper supporting units. When the lifting and pulling device is pulled upwards and drives the first linkage components and the side supporting units to be folded towards the lifting and pulling device at the center, the second linkage components and the first linkage components are in synchronous linkage, the second linkage components pull the upper supporting units to be bent and folded smoothly, and therefore the folding crib frame of the baby crib has the advantages of being fast, smooth, safe and reliable when being folded or unfolded.