In van der Waals system, the interlayer van der Waals coupling between adjacent atomically thin layers makes the electronic wave function spread on more than one specific layer, turning spatial discrete layer degree of freedom into a quantum mechanical degree of freedom. The coupling of layer degree of freedom with the in-plane center-of-mass motion of electrons forms a nontrivial layer pseudospin structure in momentum space, resulting in various new quantum geometric properties in an extended parameter space, which is unique to the lattice mismatched van der Waals systems. They trigger off a plenty of novel transport and optical effects, linear and nonlinear responses, and offer new pathways towards device applications, becoming the research frontiers of quantum layertronics. This article briefly reviews this emerging research direction, and discusses possible development in the near future based on its crossing with other intensive research fields such as nonlinear electronics, twistronics and chiral electronics.