This article explores the mathematical and physical foundations of the existence of virtual spacetime. It is pointed out that there are three forms of virtual spacetime. The first is faster-than-light virtual spacetime; The second is black hole virtual spacetime; The third is microscopic virtual spacetime. According to the characteristics of microscopic virtual spacetime, when the spacetime scale is less than a certain radius, an unobservable spacetime region will appear. This unobservable area is virtual spacetime. If the size of a particle falls within the microscopic virtual space, it means that the radius of the particle is not measurable. Naturally, there is no structure inside, just like an electron. But if the radius of the particle exceeds the boundary of spacetime, the electromagnetic radius of the particle can be observed in the real spacetime. Considering that a particle usually has many other parameters, including charge, spin, isospin, etc., this means that some more detailed structural models of the particle can be constructed according to some mathematical methods of symmetry. On this basis, this paper constructs a new model of elementary particles, which can better explain the difference between the radius and mass of electrons and protons, and can explain the properties of neutrons, bosons, neutrinos, etc.