This paper investigates the vertical vibration behavior of an innovative discretely connected precast concrete sandwich floor (DCPCF) in orthogonal slab laying direction (OSLD). An experimental program included the full-scale tests of seven DCPCF specimens and two cast-in-situ floor (CISF) specimens was conducted. In order to evaluate the vertical vibration behavior of the DCPCF, the parameters considered the number of slabs, the number of connectors, the position of slab joints and loading condition were studied according to the vibration mode, fundamental frequency, damping ratio and acceleration response. The test results indicated that the first two vibration modes of DCPCF specimens and CISF specimens were basically the same. The fundamental frequency of the DCPCF was negatively correlated with the number of slab joints and overlying loads, and positively correlated with the number of connectors and the distance of slab joints to the mid-span. The damping ratio of the DCPCF decreased with the decrease of the number of slab joints, the increase of the number of connectors and the distance of slab joints to the mid-span. The vibration response of DCPCF specimens was slightly larger than those of CISF specimens under the same excitation. The peak acceleration increased with the increase of the loading frequency and the number of pedestrians. The closer the loading distribution was to the mid-span, the greater the peak acceleration would be. Based on the vertical vibration theory of elastic thin slab, the calculation methods for predicting the first mode natural frequency and peak acceleration of the DCPCF in OSLD were proposed. The calculated results obtained by the proposed formula showed good agreement with the experiment results.