Two-dimensional (2D) van der Waals (vdW) heterostructures based on multiferroic materials have potential applications in novel low-dimensional spintronic devices. In this work, we have investigated a strong magnetoelectric coupling and electrical dependence between single layer (1L) Cr2Si2Te6 and In2Se3. By switching the direction of ferroelectric polarization in In2Se3, we observed a significant magneto-crystalline anisotropy energy (MAE) enhancement of Cr2Si2Te6. The analysis of the spin-resolved orbital-decomposed band structure shows stronger magnetoelectric coupling between the In2Se3 and Cr2Si2Te6 layers. The modulation of the electrical features could also be achieved in the switching of the ferroelectric polarization. Furthermore, the switching of Ohmic-Schottky contacts in the heterojunction with different polarization states was successfully achieved under the effect of strain engineering. Based on these findings, we design a novel 2D ferroelectric-ferromagnetic heterojunction that exploits the controllability and nonvolatility of ferroelectrics to modulate the electrical properties of the device. These findings indicate the high application potential of Cr2Si2Te6/In2Se3 multiferroic heterojunctions in spintronics.