By doping two potassium atoms among three C₂₀F₂₀ cages, peanut-shaped single molecular solvated dielectron C₂₀F₂₀@K@C₂₀F₂₀@K@C₂₀F₂₀ as new type of spin molecular switches was theoretically presented. The triplet structure with two single-excess-electrons individually inside left and middle cages is thermodynamically more stable than the singlet one with lone pair of excess electrons inside middle cage. It is found that applying an oriented external electric field (OEEF) of 111 × 10^-4 au (0.5705 V/Å) or -120 × 10^-4 au (-0.6168 V/Å) in the x-axis direction firstly and then releasing it, the field-free triplet C₂₀F₂₀@K@C₂₀F₂₀@K@C₂₀F₂₀ with two single-excess-electrons can change into singlet one with lone pair of excess electrons through a singlet one with lone pair of excess electrons inside the end cage. Different spin states can bring significantly different dipole moment component values and considerable different intensities of maxumum wavelengths in intense absorption band. Therefore, C₂₀F₂₀@K@C₂₀F₂₀@K@C₂₀F₂₀ is a good candidate for spin molecular switching materials.