Vertical counterforce loading device for large-tonnage soil material load test and loading method thereof

The vertical counterforce loading device includes a concrete support member, four transfer components, four connection components, a vertical force transmission component and a load test soil layer. The concrete support member is formed by pouring and concreting below the load test soil layer. The four transfer components are divided into two groups to be symmetrically and parallelly anchored in the concrete support member. The vertical force transmission component includes a load plate, a jack, a primary beam and a secondary beam arranged in sequence from bottom to top. The load plate is installed on the load test soil layer. Two secondary beams are connected crosswise to both ends of the primary beam, where end portions of the secondary beams are respectively connected to second ends of the connection components through reinforcement components. The device can improve work efficiency, reduce construction costs and improve safety.