In superconductors, the two electrons in a Cooper pair can form either a singlet or a triplet. A spin-triplet superconductor has profound connection to topological superconductor, which holds promises for Majorana quasiparticles and quantum computing, and also spin supercurrent. Most superconductors are spin-singlet. Intrinsic spin-triplet superconductors are rare, but there are promising candidates, including β-Bi2Pd, UTe2 and the most recent development of graphene moiré superlattice. We use phase- and spin-sensitive methods to identify and explore spin-triplet superconductors.