主要是写Tuple(Tbl.a, Tbl.b).in_(...)：

class Reg(db.Model):
    key = TextField()
    value = IntegerField()

db.create_tables([Reg])
for i in range(10):
    for j in range(10):
        Reg.create(key='k%s' % i, value=j)

vals = [('k%s' % i, i) for i in range(10)]
q = Reg.select().where(Tuple(Reg.key, Reg.value).in_(vals))
for row in q:
    print(row.key, row.value)

输出：

k0 0
k1 1
k2 2
k3 3
k4 4
k5 5
k6 6
k7 7
k8 8
k9 9